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Title: A Guide to the Study of Fishes, Volume 2 (of 2)
Author: Jordan, David Starr
Language: English
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Copyright Status: Not copyrighted in the United States. If you live elsewhere check the laws of your country before downloading this ebook. See comments about copyright issues at end of book.

*** Start of this Doctrine Publishing Corporation Digital Book "A Guide to the Study of Fishes, Volume 2 (of 2)" ***

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                      GUIDE TO THE STUDY OF FISHES


[Illustration:

  VARIATIONS IN THE COLOR OF FISHES

  The Oniokose or Demon Stinger, _Inimicus japonicus_ (Cuv. and Val.),
    from Wakanoura, Japan. From nature by Kako Morita.

  Surface coloration about lava rocks.

  Coloration of specimens living among red algæ.

  Coloration in deep water; _Inimicus aurantiacus_ (Schlegel).
]



                                A GUIDE
                                   TO
                          THE STUDY OF FISHES


                                   BY

                           DAVID STARR JORDAN

            _President of Leland Stanford Junior University_


           _With Colored Frontispieces and 507 Illustrations_


                             IN TWO VOLUMES

                                VOL II.

                             "I am the wiser in respect to all knowledge
                             and the better qualified for all fortunes
                             for knowing that there is a minnow in that
                             brook."—_Thoreau_

[Illustration]

                                NEW YORK
                         HENRY HOLT AND COMPANY
                                  1905



                            Copyright, 1905

                                   BY

                         HENRY HOLT AND COMPANY


                         Published March, 1905



                                CONTENTS
                                VOL. II.


                               CHAPTER I.

                              THE GANOIDS.

                                                                    PAGE

 Subclass Actinopteri.—The Series Ganoidei.—Are the Ganoids a          1
   Natural Group?—Systematic Position of Lepidosteus.—Gill on the
   Ganoids as a Natural Group.

                               CHAPTER II.

                       THE GANOIDS (_Continued_).

 Classification of Ganoids.—Order Lysopteri.—The Palæoniscidæ.—The    13
   Platysomidæ.—The Dorypteridæ.—The Dictyopygidæ.—Order
   Chondrostei.—Order Selachostomi: the Paddle-fishes.—Order
   Pycnodonti.—Order Lepidostei.—Family Lepisosteidæ.—Embryology of
   the Garpike.—Fossil Garpikes.—Order Halecomorphi.—Pachycormidæ.—
   The Bowfins: Amiidæ.—The Oligopleuridæ.

                              CHAPTER III.

                              ISOSPONDYLI.

 The Subclass Teleostei, or Bony Fishes.—Order Isospondyli.—The       37
   Classification of the Bony Fishes.—Relationships of
   Isospondyli.—The Clupeoidea.—The Leptolepidæ.—The Elopidæ.—The
   Albulidæ.—The Chanidæ.—The Hiodontidæ.—The Pterothrissidæ.—The
   Ctenothrissidæ.—The Notopteridæ.—The Clupeidæ.—The
   Dorosomatidæ.—The Engraulididæ.—Gonorhynchidæ.—The
   Osteoglossidæ.—The Pantodontidæ.

                               CHAPTER IV.

                               SALMONIDÆ.

 The Salmon Family.—Coregonus, the Whitefish.—Argyrosomus, the Lake   61
   Herring.—Brachymystax and Stenodus, the Inconnus.—Oncorhynchus,
   the Quinnat Salmon.—The Parent-stream Theory.—The Jadgeska
   Hatchery.—Salmon-packing.


                               CHAPTER V.

                        SALMONIDÆ (_Continued_).

 Salmo, the Trout and Atlantic Salmon.—The Atlantic Salmon.—The       89
   Ouananiche.—The Black-spotted Trout.—The Trout of Western
   America.—Cutthroat or Red-throated Trout.—Hucho, the Huchen.—
   Salvelinus, the Charr.—Cristivomer, the Great Lake Trout.—The
   Ayu, or Sweetfish.—Cormorant-fishing.—Fossil Salmonidæ.

                               CHAPTER VI.

                       THE GRAYLING AND THE SMELT.

 The Grayling, or Thymallidæ.—The Argentinidæ.—The Microstomidæ.—    120
   The Salangidæ, or Icefishes.—The Haplochitonidæ.—Stomiatidæ.—
   Suborder Iniomi, the Lantern-fishes.—Aulopidæ.—The
   Lizard-fishes.—Ipnopidæ.—Rondeletiidæ.—Myctophidæ.—
   Chirothricidæ.—Maurolicidæ.—The Lancet-fishes.—The
   Sternoptychidæ.—Order Lyopomi.

                              CHAPTER VII.

                     THE APODES, OR EEL-LIKE FISHES.

 The Eels.—Order Symbranchia.—Order Apodes, or True Eels.—Suborder   139
   Archencheli.—Suborder Enchelycephali.—Family Anguillidæ.—
   Reproduction of the Eel.—Food of the Eel.—Larva of the Eel.—
   Species of Eels.—Pug-nosed Eels.—Conger-eels.—The Snake-eels.—
   Suborder Colocephali, or Morays.—Family Moringuidæ.—Order
   Carencheli, the Long-necked Eels.—Order Lyomeri or Gulpers.—
   Order Heteromi.

                              CHAPTER VIII.

                          SERIES OSTARIOPHYSI.

 Ostariophysi.—The Heterognathi.—The Eventognathi.—The Cyprinidæ.—   159
   Species of Dace and Shiner.—Chubs of the Pacific Slope.—The Carp
   and Goldfish.—The Catostomidæ.—Fossil Cyprinidæ.—The Loaches.

                               CHAPTER IX.

                     THE NEMATOGNATHI, OR CATFISHES.

 The Nematognathi.—Families of Nematognathi.—The Siluridæ.—The Sea   177
   Catfish.—The Channel Cats.—Horned Pout.—The Mad-toms.—The Old
   World Catfishes.—The Sisoridæ.—The Plotosidæ.—The Chlariidæ.—The
   Hypophthalmidæ or Pygidiidæ.—The Loricariidæ.—The
   Callichthyidæ.—Fossil Catfishes.—Order Gymnonoti.


                               CHAPTER X.

                  THE SCYPHOPHORI, HAPLOMI, AND XENOMI.

 Order Scyphophori.—The Mormyridæ.—The Haplomi.—The Pikes.—The Mud   188
   minnows.—The Killifishes.—Amblyopsidæ.—Kneriidæ, etc.—The
   Galaxiidæ.—Order Xenomi.

                               CHAPTER XI.

                     ACANTHOPTERYGII; SYNENTOGNATHI.

 Order Acanthopterygii, the Spiny-rayed Fishes.—Suborder             208
   Synentognathi.—The Garfishes: Belonidæ.—The Flying-fishes:
   Exocœtidæ.

                              CHAPTER XII.

                       PERCESOCES AND RHEGNOPTERI.

 Suborder Percesoces.—The Silversides: Atherinidæ.—The Mullets:      215
   Mugilidæ.—The Barracudas: Sphyrænidæ.—Stephanoberycidæ.—
   Crossognathidæ.—Cobitopsidæ.—Suborder Rhegnopteri.

                              CHAPTER XIII.

            PHTHINOBRANCHII: HEMIBRANCHII, LOPHOBRANCHII, AND

                              HYPOSTOMIDES.

 Suborder Hemibranchii.—The Sticklebacks: Gasterosteidæ.—The         227
   Aulorhynchidæ.—Cornet-fishes: Fistulariidæ.—The Trumpet-fishes:
   Aulostomidæ.—The Snipefishes: Macrorhamphosidæ.—The
   Shrimp-fishes: Centriscidæ.—The Lophobranchs.—The
   Solenostomidæ.—The Pipefishes: Syngnathidæ.—The Sea-horses:
   Hippocampus.—Suborder Hypostomides, the Sea-moths: Pegasidæ.

                              CHAPTER XIV.

                SALMOPERCÆ AND OTHER TRANSITIONAL GROUPS.

 Suborder Salmopercæ, the Trout-perches: Percopsidæ.—                241
   Erismatopteridæ.—Suborder Selenichthyes, the Opahs: Lamprididæ.—
   Suborder Zeoidea.—Amphistiidæ.—The John Dories: Zeidæ.—
   Grammicolepidæ.

                               CHAPTER XV.

                               BERYCOIDEI.

 The Berycoid Fishes.—The Alfonsinos: Berycidæ.—The Soldier-fishes:  250
   Holocentridæ.—The Polymixiidæ.—The Pine-cone Fishes:
   Monocentridæ.


                              CHAPTER XVI.

                              PERCOMORPHI.

 Suborder Percomorphi, the Mackerels and Perches.—The Mackerel       258
   Tribe: Scombroidea.—The True Mackerels: Scombridæ.—The Escolars:
   Gempylidæ.—Scabbard and Cutlass-fishes: Lepidopidæ and
   Trichiuridæ.—The Palæorhynchidæ.—The Sailfishes: Istiophoridæ.—
   The Swordfishes: Xiphiidæ.

                              CHAPTER XVII.

                         CAVALLAS AND PAMPANOS.

 The Pampanos: Carangidæ.—The Papagallos: Nematistiidæ.—The          272
   Bluefishes: Cheilodipteridæ.—The Sergeant-fishes:
   Rachycentridæ.—The Butter-fishes: Stromateidæ.—The Rag-fishes:
   Icosteidæ.—The Pomfrets: Bramidæ.—The Dolphins: Coryphænidæ.—The
   Menidæ.—The Pempheridæ.—Luvaridæ.—The Square-tails:
   Tetragonuridæ.—The Crested Bandfishes: Lophotidæ.

                             CHAPTER XVIII.

                    PERCOIDEA, OR PERCH-LIKE FISHES.

 Percoid Fishes.—The Pirate-perches: Aphredoderidæ.—The Pigmy        293
   Sunfishes: Elassomidæ.—The Sunfishes: Centrarchidæ.—Crappies and
   Rock Bass.—The Black Bass.—The Saleles: Kuhliidæ.—The True
   Perches: Percidæ.—Relations of Darters to Perches.—The Perches.—
   The Darters: Etheostominæ.

                              CHAPTER XIX.

                      THE BASS AND THEIR RELATIVES.

 The Cardinal-fishes: Apogonidæ.—The Anomalopidæ.—The Asineopidæ—    316
   The Robalos: Oxylabracidæ.—The Sea-bass: Serranidæ.—The
   Jewfishes.—The Groupers.—The Serranos.—The Flashers: Lobotidæ.—
   The Big eyes: Priacanthidæ.—The Pentacerotidæ.—The Snappers:
   Lutianidæ.—The Grunts: Hæmulidæ.—The Porgies: Sparidæ.—The
   Picarels: Mænidæ.—The Mojarras: Gerridæ.—The Rudder-fishes:
   Kyphosidæ.

                               CHAPTER XX.

            THE SURMULLETS, THE CROAKERS AND THEIR RELATIVES.

 The Surmullets, or Goatfishes: Mullidæ.—The Croakers: Sciænidæ.—    351
   The Sillaginidæ, etc.—The Jawfishes: Opisthognathidæ, etc.—The
   Stone-wall Perch: Oplegnathidæ.—The Swallowers: Chiasmodontidæ.—
   The Malacanthidæ.—The Blanquillos: Latilidæ.—The Bandfishes:
   Cepolidæ.—The Cirrhitidæ.—The Sandfishes: Trichodontidæ.


                              CHAPTER XXI.

                       LABYRINTHICI AND HOLCONOTI.

 The Labyrinthine Fishes.—The Climbing-perches: Anabantidæ.—The      365
   Gouramis: Osphromenidæ.—The Snake-head Mullets: Ophicephalidæ.—
   Suborder Holconoti, the Surf-fishes.—The Embiotocidæ.

                              CHAPTER XXII.

                      CHROMIDES AND PHARYNGOGNATHI.

 Suborder Chromides.—The Cichlidæ.—The Damsel-fishes:                380
   Pomacentridæ.—Suborder Pharyngognathi.—The Wrasse Fishes:
   Labridæ.—The Parrot-fishes: Scaridæ.

                             CHAPTER XXIII.

                            THE SQUAMIPINNES.

 The Squamipinnes.—The Scorpididæ.—The Boarfishes: Antigoniidæ.—The  397
   Arches: Toxotidæ.—The Ephippidæ.—The Spadefishes: Ilarchidæ.—The
   Platacidæ.—The Butterfly-fishes: Chætodontidæ.—The Pygæidæ.—The
   Moorish Idols: Zanclidæ.—The Tangs: Acanthuridæ.—Suborder
   Amphacanthi, the Siganidæ.

                              CHAPTER XXIV.

                          SERIES PLECTOGNATHI.

 The Plectognaths.—The Scleroderms.—The Trigger-fishes: Balistidæ.—  411
   The File-fishes: Monacanthidæ.—The Spinacanthidæ.—The
   Trunkfishes: Ostraciidæ.—The Gymnodontes.—The Triodontidæ.—The
   Globefishes: Tetraodontidæ.—The Porcupine-fishes: Diodontidæ.—
   The Head-fishes: Molidæ.

                              CHAPTER XXV.

                  PAREIOPLITÆ, OR MAILED-CHEEK FISHES.

 The Mailed-cheek Fishes.—The Scorpion-fishes: Scorpænidæ.—The       426
   Skilfishes: Anoplopomidæ.—The Greenlings: Hexagrammidæ.—The
   Flatheads or Kochi: Platycephalidæ.—The Sculpins: Cottidæ.—The
   Sea-poachers: Agonidæ.—The Lump-suckers: Cyclopteridæ.—The
   Sea-snails: Liparididæ.—The Baikal Cods: Comephoridæ.—Suborder
   Craniomi: the Gurnards, Triglidæ.—The Peristediidæ.—The Flying
   Gurnards: Cephalacanthidæ.

                              CHAPTER XXVI.

                 GOBIOIDEI, DISCOCEPHALI, AND TÆNIOSOMI.

 Suborder Gobioidei, the Gobies: Gobiidæ.—Suborder Discocephali,     459
   the Shark-suckers: Echeneididæ.—Suborder Tæniosomi, the
   Ribbon-fishes.—The Oarfishes: Regalecidæ.—The Dealfishes:
   Trachypteridæ.


                             CHAPTER XXVII.

                         SUBORDER HETEROSOMATA.

 The Flatfishes.—Optic Nerves of Flounders.—Ancestry of Flounders.—  481
   The Flounders: Pleuronectidæ.—The Turbot Tribe: Bothinæ.—The
   Halibut Tribe: Hippoglossinæ.—The Plaice Tribe: Pleuronectinæ.—
   The Soles: Soleidæ.—The Broad Soles: Achirinæ.—The European
   Soles (Soleinæ).—The Tongue-fishes: Cynoglossinæ.

                             CHAPTER XXVIII.

                           SUBORDER JUGULARES.

 The Jugular-fishes.—The Weevers: Trachinidæ.—The Nototheniidæ.—The  499
   Leptoscopidæ.—The Star-gazers: Uranoscopidæ.—The Dragonets:
   Callionymidæ.—The Dactyloscopidæ.

                              CHAPTER XXIX.

                        THE BLENNIES: BLENNIIDÆ.

 The Northern Blennies: Xiphidiinæ, Stichæiniæ, etc.—The             507
   Quillfishes: Ptilichthyidæ.—The Blochiidæ.—The Patæcidæ, etc.—
   The Gadopsidæ, etc.—The Wolf-fishes: Anarhichadidæ.—The
   Eel-pouts: Zoarcidæ.—The Cusk-eels: Ophidiidæ.—Sand-lances:
   Ammodytidæ.—The Pearlfishes: Fierasferidæ.—The Brotulidæ.—
   Ateleopodidæ.—Suborder Haplodoci.—Suborder Xenopterygii.

                              CHAPTER XXX.

                       OPISTHOMI AND ANACANTHINI.

 Order Opisthomi.—Order Anacanthini.—The Codfishes: Gadidæ.—The      532
   Hakes: Merluciidæ.—The Grenadiers: Macrouridæ.

                              CHAPTER XXXI.

                     ORDER PEDICULATI: THE ANGLERS.

 The Angler-fishes.—The Fishing-frogs: Lophiidæ.—The Sea-devils:     542
   Ceratiidæ.—The Frogfishes: Antennariidæ.—The Batfishes:
   Ogcocephalidæ.



                         LIST OF ILLUSTRATIONS
                                VOL. II.


                                                                    PAGE

 Shoulder-girdle of a Flounder, _Paralichthys californicus_            2

 _Palæoniscum frieslebenense_                                         14

 _Eurynotus crenatus_                                                 15

 _Dorypterus hoffmani_                                                16

 _Chondrosteus acipenseroides_                                        18

 _Acipenser sturio_, Common Sturgeon                                  19

 _Acipenser rubicundus_, Lake Sturgeon                                20

 _Scaphirhynchus platyrhynchus_, Shovel-nosed Sturgeon                20

 _Polyodon spathula_, Paddle-fish, side-view                          21

 _Polyodon spathula_, Paddle-fish, view from below                    21

 _Psephurus gladius_                                                  21

 _Gyrodus hexagonus_                                                  22

 _Mesturus verrucosus_                                                23

 _Semionotus kapffi_                                                  24

 _Dapedium politum_                                                   25

 _Tetragonolepis semicinctus_                                         26

 _Isopholis orthostomus_                                              27

 _Lepisosteus osseus_, Long-nosed Garpike                             27

 _Caturus elongatus_                                                  28

 _Notagogus pentlandi_                                                28

 _Ptycholepis curtus_                                                 28

 _Pholidophorus crenulatus_                                           29

 _Lepisosteus tristœchus_, Alligator-gar                              31

 Lower Jaw of _Amia calva_, showing the gular plate                   33

 _Amia calva_, Bowfin (female)                                        35

 _Megalurus elegantissimus_                                           36

 _Leptolepis dubius_                                                  41

 _Elops saurus_, Ten-pounder                                          42

 _Holcolepis lewesiensis_                                             42

 _Tarpon atlanticus_, Tarpon or Grand Écaille                         43

 _Albula vulpes_, Lady-fish                                           44

 _Chanos chanos_, Milkfish                                            45

 _Hiodon tergisus_, Mooneye                                           45

 _Istieus grandis_                                                    46

 _Chirothrix libanicus_                                               46

 Skeleton of _Portheus molossus_                                      47

 _Ctenothrissa vexillifera_                                           48

 _Clupea harengus_, Herring                                           49

 _Pomolobus pseudoharengus_, Alewife                                  50

 _Brevoortia tyrannus_, Menhaden                                      51

 _Diplomystus humilis_                                                52

 _Dorosoma cepedianum_, Hickory-shad                                  53

 _Anchovia perthecata_, Silver Anchovy                                54

 _Notogoneus osculus_                                                 55

 _Phareodus testis_                                                   57

 Deposits of Green River Shales, bearing _Phareodus_, at Fossil,      58
   Wyoming

 A Day's Catch of fossil-fishes, Green River Eocene Shales            59

 _Alepocephalus agassizii_                                            60

 _Coregonus williamsoni_, Rocky Mountain Whitefish                    63

 _Coregonus clupeiformis_, Whitefish                                  64

 _Argyrosomus nigripinnis_, Bluefin Cisco                             66

 _Stenodus mackenziei_, Inconnu                                       67

 _Oncorhynchus tschawytscha_, Quinnat Salmon (female)                 69

 _Oncorhynchus tschawytscha_, King-salmon (grilse)                    70

 _Oncorhynchus nerka_, Male Red Salmon                                70

 _Oncorhynchus gorbuscha_, Humpback Salmon (female)                   72

 _Oncorhynchus masou_, Masu                                           72

 _Oncorhynchus nerka_, Red Salmon (mutilated dwarf male after         76
   spawning)

 _Oncorhynchus tschawytscha_, Quinnat Salmon (dying after spawning)   77

 _Oncorhynchus tschawytscha_, Quinnat Salmon                          79

 _Salmo irideus shasta_, Rainbow Trout (male)                         98

 _Salmo irideus shasta_, Rainbow Trout (female)                       99

 _Salmo rivularis_, Steelhead Trout                                  101

 Head of Adult Trout-worm, _Dibothrium cordiceps_. From intestine    103
   of white pelican

 Median segments of _Dibothrium cordiceps_                           103

 _Salmo henshawi_, Tahoe Trout                                       104

 _Salmo stomias_, Green-back Trout                                   105

 _Salmo macdonaldi_, Yellow-fin Trout of Twin Lakes                  105

 _Salmo clarkii spilurus_, Rio Grande Trout                          106

 _Salmo clarkii pleuriticus_, Colorado River Trout                   106

 _Hucho blackistoni_, Ito                                            107

 _Salvelinus oquassa_, Rangeley Trout                                108

 _Salvelinus aureolus_, Sunapee Trout                                109

 _Salvelinus fontinalis_, Speckled Trout (male)                      110

 _Salvelinus fontinalis_, Speckled Trout                             111

 _Salvelinus malma_, Malma Trout                                     113

 _Salvelinus malma_, Dolly Varden Trout                              114

 _Cristivomer namaycush_, Great Lake Trout                           114

 _Plecoglossus altivelis_, Ayu, or Japanese Samlet                   116

 _Thymallus signifer_, Alaska Grayling                               120

 _Thymallus tricolor_, Michigan Grayling                             122

 _Osmerus mordax_, Smelt                                             123

 _Thaleichthys pretiosus_, Eulachon or Ulchen                        124

 Page of William Clark's Handwriting with Sketch of the Eulachon     125
   (_Thaleichthys pacificus_)

 _Mallotus villosus_, Capelin                                        126

 _Salanx hyalocranius_, Icefish                                      128

 _Stomias ferox_                                                     128

 _Chauliodus sloanei_                                                129

 _Synodus fætens_, Lizard-fish                                       130

 _Ipnops murrayi_                                                    131

 _Cetomimus gillii_                                                  132

 _Diaphus lucidus_, Headlight-fish                                   132

 _Myctophum opalinum_, Lantern-fish                                  133

 _Ceratoscopelus madeirensis_, Lantern-fish                          133

 _Rhinellus furcatus_                                                134

 _Plagyodus ferox_, Lancet-fish                                      135

 _Eurypholis sulcidens_                                              136

 _Eurypholis freyeri_                                                137

 _Argyropelecus olfersi_                                             137

 _Aldrovandia gracilis_                                              138

 _Anguilla chrisypa_, Common Eel                                     143

 _Anguilla chrisypa_, Larva of Common Eel                            148

 _Simenchelys parasiticus_, Pug-nosed Eel                            149

 _Synaphobranchus pinnatus_                                          149

 _Leptocephalus conger_, Conger-eel                                  150

 Larva of Conger-eel, _Leptocephalus conger_                         150

 _Xyrias revulsus_                                                   151

 _Myrichthys pantostigmius_                                          151

 _Ophichthus ocellatus_                                              151

 _Nemichthys avocetta_, Thread-eel                                   152

 Jaws of _Nemichthys avocetta_                                       152

 _Muræna retifera_                                                   153

 _Gymnothorax berndti_                                               154

 _Gymnothorax jordani_                                               155

 _Gymnothorax moringa_, Moray                                        155

 _Derichthys serpentinus_                                            156

 _Gastrostomus bairdi_, Gulper-eel                                   156

 _Notacanthus phasganorus_                                           158

 Inner view of shoulder-girdle of Buffalo-fish (_Ictiobus            160
   bubalus_), showing the mesocoracoid

 Weberian apparatus and air-bladder of Carp                          160

 _Brycon dentex_                                                     162

 Pharyngeal bones and teeth of European Chub, _Leuciscus cephalus_   163

 _Rhinichthys dulcis_, Black-nosed Dace                              164

 _Notropis hudsonius_, White Chub                                    165

 _Ericymba buccata_, Silver-jaw Minnow                               165

 _Notropis whipplei_, Silverfin                                      166

 _Campostoma anomalum_, Stone-roller                                 167

 Head of Day-chub, _Exoglossum maxillingua_                          167

 _Semotilus atromaculatus_, Horned Dace                              168

 _Abramis chrysoleucus_, Shiner                                      168

 _Ptychocheilus grandis_, Squawfish                                  169

 _Leuciscus lineatus_, Chub of the Great Basin                       169

 Lower Pharyngeal of _Placopharynx duquesnii_                        171

 _Erimyzon sucetta_, Creekfish or Chub-sucker                        172

 _Ictiobus cyprinella_, Buffalo-fish                                 173

 _Carpiodes cyprinus_, Carp-sucker                                   173

 _Catostomus commersoni_, Common Sucker                              174

 _Catostomus occidentalis_, California Sucker                        174

 Pharyngeal teeth of Oregon Sucker, _Catostomus macrocheilus_        175

 _Xyrauchen cypho_, Razor-back Sucker                                175

 _Felichthys felis_, Gaff-topsail Cat                                179

 _Galeichthys milberti_, Sea Catfish                                 179

 _Ictalurus punctatus_, Channel Catfish                              180

 _Ameiurus nebulosus_, Horned Pout                                   181

 _Schilbeodes furiosus_, Mad-tom. Showing the poisoned pectoral      182
   spine

 _Torpedo electricus_, Electric Catfish                              183

 _Chlarias breviceps_, African Catfish                               185

 _Loricaria aurea_, Mailed Catfish from Venezuela                    186

 _Gnathonemus curvirostris_                                          189

 _Esox lucius_, Pike                                                 191

 _Esox masquinongy_, Muskallunge                                     192

 _Umbra pygmæa_, Mud-minnow                                          193

 _Anableps dovii_, Four-eyed Fish                                    195

 _Cyprinodon variegatus_, Round Minnow                               196

 _Jordanella floridæ_, Everglade Minnow                              197

 _Fundulis majalis_, Mayfish (male)                                  198

 _Fundulis majalis_, Mayfish (female)                                198

 _Zygonectes notatus_, Top-minnow                                    198

 _Empetrichthys merriami_, Death Valley Fish                         199

 _Xiphophorus helleri_, Sword-tail Minnow (male)                     199

 _Goodea luitpoldi_, a Viviparous Fish                               200

 _Chologaster cornutus_, Dismal Swamp Fish                           201

 _Typhlichthys subterraneus_, Blind Cave-fish                        202

 _Amblyopsis spelæus_, Blindfish of the Mammoth Cave                 203

 _Dallia pectoralis_, Alaska Blackfish                               206

 _Tylosurus acus_, Needle-fish                                       210

 _Scombresox saurus_, Saury                                          212

 _Hyporhamphus unifasciatus_, Halfbeak                               212

 _Fodiator acutus_, Sharp-nosed Flying-fish                          213

 _Cypselurus californicus_, Catalina Flying-fish                     214

 _Chirostoma humboldtianum_, Pescado blanco                          217

 _Kirtlandia vagrans_, Silverside or Brit                            217

 _Atherinopsis californiensis_, Blue Smelt or Pez del Rey            218

 _Iso flos-maris_, Flower of the Waves                               218

 _Mugil cephalus_, Striped Mullet                                    221

 _Joturus pichardi_, Joturo or Bobo                                  222

 _Sphyræna barracuda_, Barracuda                                     223

 _Cobitopsis acuta_                                                  224

 Shoulder-girdle of a Threadfin, _Polydactylus approximans_          225

 _Polydactylus octonemus_, Threadfin                                 225

 Shoulder-girdle of a Stickleback, _Gasterosteus aculeatus_          227

 Shoulder-girdle of _Fistularia petimba_, showing greatly extended   227
   interclavicle, the surface ossified

 _Gasterosteus aculeatus_, Three-spined Stickleback                  232

 _Apeltes quadracus_, Four-spined Stickleback                        232

 _Aulostomus chinensis_, Trumpet-fish                                234

 _Macrorhamphosus sagifue_, Japanese Snipefish                       234

 _Æoliscus strigatus_, Shrimp-fish                                   235

 _Æoliscus heinrichi_                                                235

 _Solenostomus cyanopterus_                                          237

 _Hippocampus hudsonius_, Sea-horse                                  238

 _Zalises umitengu_, Sea-moth                                        240

 _Percopsis guttatus_, Sand-roller                                   241

 _Erismatopterus endlicheri_                                         242

 _Columbia transmontana_, Oregon Trout-perch                         242

 Shoulder-girdle of the Opah, _Lampris guttatus_ (_Brünnich_),       243
   showing the enlarged infraclavicle

 Ligatures_Semiophorus velifer_                                      246

 _Amphistium paradoxum_                                              247

 _Zeus faber_, John Dory                                             248

 Skull of a Berycoidfish, _Beryx splendens_, showing the             250
   orbitosphenoid

 _Beryx splendens_                                                   251

 _Hoplopteryx lewesiensis_                                           252

 _Paratrachichthys prosthemius_                                      253

 _Holocentrus ascenscionis_, Soldier-fish                            254

 _Holocentrus ittodai_                                               254

 _Ostichthys japonicus_                                              255

 _Monocentris japonicus_, Pine-cone Fish                             256

 _Scomber scombrus_, Mackerel                                        260

 _Germo alalunga_, Long-fin Albacore                                 263

 _Scomberomorus maculatus_, Spanish Mackerel                         264

 _Trichiurus lepturus_, Cutlass-fish                                 268

 _Palæorhynchus glarisianus_                                         268

 _Xiphias gladius_, Young Swordfish                                  269

 _Xiphias gladius_, Swordfish                                        270

 _Naucrates ductor_, Pilot-fish                                      273

 _Seriola lalandi_, Amber-fish                                       273

 _Trachurus trachurus_, Saurel                                       274

 _Carangus chrysos_, Yellow Mackerel                                 275

 _Trachinotus carolinus_, the Pampano                                277

 _Cheilodipterus saltatrix_, Bluefish                                279

 _Rachycentron canadum_, Sergeant-fish                               282

 _Peprilus paru_, Harvest-fish                                       284

 _Gobiomorus gronovii_, Portuguese Man-of-War Fish                   285

 _Coryphæna hippurus_, Dolphin or Dorado                             287

 _Mene maculata_                                                     288

 _Gasteronemus rhombeus_                                             289

 _Pempheris mulleri_, Catalufa de lo Alto                            289

 _Pempheris nyctereutes_                                             290

 _Luvarus imperialis_, Louvar                                        290

 _Aphredoderus sayanus_, Pirate Perch                                295

 _Elassoma evergladei_, Everglade Pigmy Perch                        295

 Skull of the Rock Bass, _Ambloplites rupestris_                     296

 _Pomoxis annularis_, Crappie                                        297

 _Pomoxis annularis_, Crappie (from life)                            298

 _Ambloplites rupestris_, Rock Bass                                  299

 _Mesogonistius chætodon_, Banded Sunfish                            299

 _Lepomis pallidus_, Blue-gill                                       300

 _Lepomis megalotis_, Long-eared Sunfish                             300

 _Eupomotis gibbosus_, Common Sunfish                                301

 _Micropterus dolomieu_, Small Mouth Black Bass                      303

 _Micropterus salmoides_, Large Mouth Black Bass                     305

 _Perca flavescens_, Yellow perch                                    308

 _Stizostedion canadense_, Sauger                                    309

 _Aspro asper_, Aspron                                               309

 _Zingel zingel_, Zingel                                             310

 _Percina caprodes_, Log-perch                                       311

 _Hadropterus aspro_, Black-sided Darter                             311

 _Diplesion blennioides_, Green-sided Darter                         312

 _Boleosoma olmstedi_, Tessellated Darter                            312

 _Crystallaria asprella_, Crystal Darter                             313

 _Ammocrypta clara_, Sand-darter                                     313

 _Etheostoma jordani_                                                314

 _Etheostoma camurum_, Blue-breasted Darter                          314

 _Apogon retrosella_, Cardinal-fish                                  316

 _Telescopias gilberti_, Kuromutsu                                   318

 _Apogon semilineatus_                                               319

 _Oxylabrax undecimalis_, Robalo                                     319

 _Morone americana_, White Perch                                     322

 _Promicrops itaiara_, Florida Jewfish                               323

 _Epinephelus striatus_, Nassau Grouper: _Cherna criolla_            324

 _Epinephelus drummond-hayi_, John Paw or Speckled Hind              325

 _Epinephelus morio_, Red Grouper                                    325

 _Epinephelus adscensionis_, Red Hind                                326

 _Mycteroperca venenosa_, Yellow-fin Grouper                         327

 _Hypoplectrus unicolor nigricans_                                   328

 _Epinephelus niveatus_, Snowy Grouper                               329

 _Rypticus bistrispinus_, Soapfish                                   330

 _Lobotes surinamensis_, Flasher                                     331

 _Priacanthus arenatus_, Catalufa                                    331

 _Pseudopriacanthus altus_, Bigeye                                   332

 _Lutianus griseus_, Gray Snapper                                    334

 _Lutianus apodus_, Schoolmaster                                     335

 _Hoplopagrus guntheri_                                              336

 _Lutianus synagris_, Lane Snapper or Biajaiba                       336

 _Ocyurus chrysurus_, Yellow-tail Snapper                            337

 _Etelis oculatus_, Cachucho                                         337

 _Xenocys jessiæ_                                                    338

 _Aphareus furcatus_                                                 339

 _Hæmulon plumieri_, Grunt                                           340

 _Anisotremus virginicus_, Porkfish                                  341

 _Pagrus major_, Red Tai of Japan                                    342

 _Ebisu_, the Fish-god of Japan, bearing a Red Tai                   343

 _Stenotomus chrysops_, Scup                                         344

 _Calamus bajonado_, Jolt-head Porgy                                 345

 _Calamus proridens_, Little-head Porgy                              345

 _Diplodus holbrooki_                                                346

 _Archosargus unimaculatus_, Salema, Striped Sheepshead              347

 _Xystæma cinereum_, Mojarra                                         348

 _Gerres olisthostomus_, Irish Pampano                               349

 _Kyphosus sectatrix_, Chopa or Rudder-fish                          349

 _Apomotis cyanellus_, Blue-green Sunfish                            350

 _Pseudupeneus maculatus_, Red Goatfish or Salmonete                 351

 _Mullus auratus_, Golden Surmullet                                  352

 _Cynoscion nebulosus_, Spotted Weakfish                             353

 _Bairdiella chrysura_, Mademoiselle                                 355

 _Sciænops ocellata_, Red Drum                                       356

 _Umbrina sinaloæ_, Yellow-fin Roncador                              357

 _Menticirrhus americanus_, Kingfish                                 357

 _Pogonias chromis_, Drum                                            358

 _Gnathypops evermanni_                                              359

 _Opisthognathus macrognathus_, Jawfish                              359

 _Opisthognathus nigromarginatus_                                    360

 _Chiasmodon niger_, Black Swallower                                 360

 _Cirrhitus rivulatus_                                               364

 _Trichodon trichodon_, Sandfish                                     364

 _Anabas scandens_, Climbing Perch                                   366

 _Channa formosana_                                                  371

 _Ophicephalus barca_, Snake-headed China-fish                       371

 _Cymatogaster aggregatus_, White Surf-fish                          372

 _Hysterocarpus traski_, Fresh-water Viviparous Perch                373

 _Hypsurus caryi_                                                    373

 _Damalichthys argyrosomus_, White Surf-fish                         374

 _Rhacochilus toxotes_, Thick-lipped Surf-fish                       374

 _Hypocritichthys analis_, Silver Surf-fish, Viviparous              375

 _Hysterocarpus traski_, Viviparous Perch (male)                     379

 _Hypsypops rubicunda_, Garibaldi                                    382

 _Pomacentrus leucostictus_, Damsel-fish                             382

 _Glyphisodon marginatus_, Cockeye Pilot                             383

 _Microspathodon dorsalis_, Indigo Damsel-fish                       384

 _Tautoga onitis_, Tautog                                            384

 _Tautoga onitis_, Tautog                                            386

 _Lachnolaimus falcatus_, Capitaine or Hogfish                       387

 _Xyrichthys psittacus_, Razor-fish                                  388

 _Pimelometopon pulcher_, Redfish (male)                             389

 _Lepidaplois perditio_                                              389

 Pharyngeals of Italian Parrot-fish, _Sparisoma cretense_. _a_,      391
   Upper; _b_, Lower

 Jaws of Parrot-fish, _Calotomus xenodon_                            391

 _Cryptotomus beryllinus_                                            391

 _Sparisoma hoplomystax_                                             392

 _Sparisoma abildgaardi_, Red Parrot-fish                            392

 Jaws of Blue Parrot-fish, _Scarus cæruleus_                         393

 Upper pharyngeals of a Parrot-fish, _Scarus strongylocephalus_      393

 Lower pharyngeals of a Parrot-fish, _Scarus strongylocephalus_      393

 _Scarus emblematicus_                                               394

 _Scarus cæruleus_, Blue Parrot-fish                                 394

 _Scarus vetula_, Parrot-fish                                        395

 _Halichæres bivittatus_, Slippery Dick or Doncella, a fish of the   399
   coral-reefs

 _Monodactylus argenteus_                                            397

 _Psettus sebæ_                                                      399

 _Chætodipterus faber_, Spadefish                                    401

 _Chætodon capistratus_, Butterfly-fish                              402

 _Pomacanthus arcuatus_, Black Angel-fish                            403

 _Holacanthus ciliaris_, Angel-fish or Isabelita                     404

 _Holacanthus tricolor_, Rock Beauty                                 405

 _Zanclus canescens_, Moorish Idol                                   406

 _Teuthis cæruleus_, Blue Tang                                       407

 _Teuthis bahianus_, Brown Tang                                      408

 _Balistes carolinensis_, Trigger-fish                               412

 _Osbeckia lævis_, File-fish                                         414

 _Amanses scopas_, Needle-bearing File-fish                          414

 _Stephanolepis hispidus_, Common File-fish                          415

 _Lactophrys tricornis_, Horned Trunkfish, Cowfish, or Cuckold       416

 _Ostracion cornutum_, Horned Trunkfish                              416

 _Lactophrys bicaudalis_, Spotted Trunkfish                          416

 _Lactophrys bicaudalis_, Spotted Trunkfish (face view)              417

 _Lactophrys triqueter_, Spineless Trunkfish                         417

 _Lactophrys trigonus_, Hornless Trunkfish                           418

 Skeleton of the Cowfish, _Lactophrys tricornis_                     418

 _Lagocephalus lævigatus_, Silvery Puffer                            419

 _Spheroides spengleri_, Puffer, Inflated                            420

 _Spheroides maculatus_, Puffer                                      420

 _Tetraodon meleagris_                                               421

 _Tetraodon setosus_, Bristly Globefish                              422

 _Diodon hystrix_, Porcupine-fish                                    422

 _Chilomycterus schœpfi_, Rabbit-fish                                423

 _Mola mola_, Headfish (adult)                                       424

 _Ranzania makua_, King of the Mackerel, from Honolulu               425

 _Sebastes marinus_, Rosefish                                        427

 Skull of _Scorpænichthys marmoratus_                                427

 _Sebastolobus altivelis_                                            428

 _Sebastodes mystinus_, Priest-fish                                  430

 _Sebastichthys serriceps_                                           431

 _Sebastichthys nigrocinctus_, Banded Rockfish                       432

 _Scorpæna grandicornis_, Lion-fish                                  433

 _Scorpæna mystes_, Sea-scorpion                                     434

 _Pterois volitans_, Lion-fish or Sausolele                          435

 _Emmydrichthys vulcanus_, Black Nohu or Poison-fish                 436

 _Snyderina yamanokami_                                              437

 _Trachicephalus uranoscopus_                                        438

 _Anoplopoma fimbria_, Skilfish                                      438

 _Pleurogrammus monopterygius_, Atka-fish                            439

 _Hexagrammos decagrammus_, Greenling                                440

 _Ophiodon elongatus_, Cultus Cod                                    440

 _Jordania zonope_                                                   442

 _Astrolytes notospilotus_                                           442

 _Hemilepidotus jordani_, Irish Lord                                 443

 _Triglops pingeli_                                                  443

 _Enophrys bison_, Buffalo Sculpin                                   443

 _Ceratocottus diceraus_                                             444

 _Elanura forficata_                                                 444

 _Cottus punctulatus_, Yellowstone Miller's Thumb                    444

 _Uranidea tenuis_, Miller's Thumb                                   445

 _Cottus evermanni_                                                  445

 _Cottus gulosus_, California Miller's Thumb                         446

 _Myxocephalus niger_, Pribilof Sculpin                              446

 _Myxocephalus octodecimspinosus_, 18-spined Sculpin                 447

 _Oncocottus quadricornis_                                           447

 _Blepsias cirrhosus_                                                448

 _Hemitripterus americanus_, Sea-raven                               448

 _Oligocottus maculosus_                                             449

 _Ereunias grallator_                                                450

 _Psychrolutes paradoxus_, Sleek Sculpin                             451

 _Gilbertidia sigolutes_                                             451

 _Rhamphocottus richardsoni_, Richardson's Sculpin                   451

 _Stelgis vulsus_                                                    451

 _Draciscus sachi_                                                   452

 _Pallasina barbata_, Agonoid-fish                                   453

 _Aspidophoroides monopterygius_                                     453

 _Cyclopterus lumpus_, Lumpfish                                      454

 _Crystallias matsushimæ_, Liparid                                   454

 _Neoliparis mucosus_, Snailfish                                     455

 _Prionotus evolans_, Sea-robin                                      456

 _Cephalacanthus volitans_, Flying Gurnard                           457

 _Peristedion miniatum_                                              457

 _Philypnus dormitor_, Guavina de Rio                                460

 _Eleotris pisonis_, Dormeur                                         460

 _Dormitator maculatus_, Guavina mapo                                461

 _Vireosa hanæ_                                                      461

 _Gobionellus oceanicus_, Esmeralda de Mar                           461

 _Pterogobius daimio_                                                462

 _Aboma etheostoma_, Darter Goby                                     462

 _Gillichthys mirabilis_, Long-jawed Goby                            463

 _Boleophthalmus chinensis_, Pond-skipper                            466

 _Periophthalmus barbarus_, Mud-skippy                               466

 _Eutæniichthys gillii_                                              467

 _Leptecheneis naucrates_, Sucking-fish or Pegador                   468

 _Rhombochirus osteochir_                                            469

 _Regalecus russelli_, Glesnæs Oarfish                               476

 _Trachypterus rex-salmonorum_, Dealfish or King of the Salmon       478

 Young Flounder just hatched                                         482

 _Pseudopleuronectes americanus_, Larval Flounder                    483

 Larval Stages of _Platophrys podas_, a Flounder                     484

 _Platophrys lunatus_, Peacock Flounder                              485

 Heterocercal Tail of Young Trout, _Salmo fario_                     486

 Homocercal Tail of a Flounder, _Paralichthys californicus_          486

 _Lophopsetta maculata_, Window-pane                                 487

 _Syacium papillosum_, Wide-eyed Flounder                            488

 _Etropus crossotus_                                                 489

 _Hippoglossus hippoglossus_, Halibut                                492

 _Paralichthys dentatus_, Wide-mouthed Flounder                      493

 _Liopsetta putnami_, Eel-back Flounder                              494

 _Platichthys stellatus_, Starry Flounder                            495

 _Achirus lineatus_, Hog-choker Sole                                 496

 _Symphurus plagiusa_                                                498

 _Pteropsaron evolans_                                               502

 _Bathymaster signatus_                                              503

 _Ariscopus iburius_                                                 504

 _Astroscopus guttatus_, Star-gazer                                  505

 _Neoclinus satiricus_, Sarcastic Blenny                             507

 _Gibbonsia evides_, Kelp Blenny                                     508

 _Blennius cristatus_                                                508

 _Alticus atlanticus_, Rock-skipper                                  509

 _Alticus saliens_, Lizard-skipper                                   509

 _Emblemaria atlantica_                                              510

 _Scartichthys enosimæ_, Fish of the rock-pools of the sacred        510
   island of Enoshima, Japan

 _Zacalles bryope_                                                   511

 _Bryostemma tarsodes_                                               511

 _Exerpes asper_                                                     511

 _Pholis gunnellus_, Gunnel                                          512

 _Xiphistes chirus_                                                  512

 _Ozorthe dictyogramma_                                              513

 _Stichæus punctatus_                                                513

 _Bryostemma otohime_                                                514

 _Ptilichthys goodei_, Quillfish                                     514

 _Blochius longirostris_                                             514

 _Xiphasia setifera_                                                 515

 _Cryptacanthodes maculatus_, Wrymouth                               516

 _Anarhichas lupus_, Wolf-fish                                       517

 Skull of _Anarrhichthys ocellatus_                                  517

 _Zoarces anguillaris_, Eel-pout                                     518

 _Lycodes reticulatus_, Eel-pout                                     519

 _Lycenchelys verrilli_                                              519

 _Scytalina cerdale_                                                 519

 _Rissola marginata_, Cusk-eel                                       520

 _Lycodapus dermatinus_                                              520

 _Ammodytes americanus_, Sand-lance                                  521

 _Embolichthys mitsukurii_                                           521

 _Fierasfer dubius_, Pearlfish, Embedded in Pearl                    522

 _Fierasfer acus_, Pearlfish                                         523

 _Brotula barbata_                                                   524

 _Lucifuga subterranea_, Blind Brotula                               524

 _Opsanus pardus_, Leopard Toadfish                                  525

 _Porichthys porosissimus_, Singing Fish (with Many Lateral Lines)   526

 _Aspasma ciconiæ_                                                   530

 _Caularchus mæandricus_, Clingfish                                  531

 _Mastacembelus ellipsifer_                                          532

 _Gadus callarias_, Codfish                                          533

 Skull of Haddock, _Melanogrammus æglifinus_                         536

 _Melanogrammus æglifinus_, Haddock                                  536

 _Theragra chalcogramma_, Pollock                                    537

 _Microgadus tomcod_, Tomcod                                         538

 _Lota maculosa_, Burbot                                             539

 _Enchelyopus cimbrius_, Four-bearded Rockling                       539

 _Merluccius productus_, California Hake                             540

 _Coryphænoides carapinus_, showing leptocercal tail                 540

 _Cælorhynchus carminatus_, Grenadier                                541

 _Steindachnerella argentea_                                         541

 _Lophius litulon_, Anko or Fishing-frog                             545

 _Cryptopsaras couesi_                                               547

 _Ceratias holbolli_, Deep-sea Angler                                548

 _Caulophryne jordani_                                               548

 _Pterophryne tumida_, Sargassum-fish, one of the Anglers            549

 _Antennarius nox_, Fishing-frog                                     550

 Shoulder-girdle of a Batfish, _Ogcocephalus radiatus_               551

 _Antennarius scaber_, Frogfish                                      551

 _Ogcocephalus vespertilio_                                          552

 _Ogcocephalus vespertilio_, Batfish                                 553

 _Ogcocephalus vespertilio_, Batfish                                 553



                               ERRATA[1]
                                VOL. II


 Page xviii,  line     7, for _Ophicæphalus_ read _Ophicephalus_

      xviii,    "     37, for _Mononactylus_ read _Monodactylus_

        xix,    "     33, for _Trachicephales_ read _Trachicephalus_

         xx,    "     37, for _Regaleaus glesneacsanius_ read _Regalecus
                            russelli_

        xxi,    "      2, for _Etopus_ read _Etropus_

        xxi,    "     35, for _Zoacres_ read _Zoarces_

          1,    "      7, _for_ jaws _read_ jaw

         14,    "      9, _for_ hetercoercal _read_ heterocercal

        136,    "      3, for _Evermannellus_ read _Evermannella_

        170,    "     11, _for_ the fin _read_ the dorsal fin

        171,    "     10, _for_ have _read_ has

        303, legend,      _for_ Lacepède _read_ Lacépède

        307,  line    14, _for_ vertebrate _read_ vertebral

        311,    "     12, not clearly stated. The air-bladder is least
                            developed in those species which cling
                            closest to the bottom of the stream

        350, legend,      for _Apomotes_ read _Apomotis_

        355,  line    18, _for_ ours _read_ our

        357,    "     14, _for_ chætodon _read_ Chætodon

        358,    "     17, for _Scriænidæ_ read _Sciænidæ_

        360,    "     14, for _Percesoces_ read _Percesoces_

        409,    "     16, for _naseus_ read _Naseus_

        419,    "     23, _for_ of the generic of this group _read_
                            separating the group into genera

        440,    "     17, _for_ Chinnook _read_ Chinook

        459,    "     24, _for_ but the most _read_ but most

        459,    "     25, _for_ thme _read_ them

        467,    "     14, for _Typhogobius_ read _Typhlogobius_

        472,  lines   34, _omit_ "but never in the United States".
                      35,   Specimens of _Regalecus_ have been taken at
                            Anclote Key, Florida, and at the Tortugas.

        580,  col.     3, line 17, _for_ 165 _read_ 105

The adoption of the Code of the International Congress of Zoology
necessitates a few changes in generic names used in this book.

      Thus _Amia_ (ganoid)                becomes _Amiatus_
           _Apogon_                       becomes _Amia_
           _Scarus_                       becomes _Callyodon_
           _Teuthis_                      becomes _Hepatus_
           _Acanthurus_                   becomes _Monoceros_
           _Paramia_                      becomes _Cheilodipterus_
           _Centropomus_ (_Oxylabrax_)    remains _Centropomus_
           _Lucioperca_ (_Centropomus_)   becomes _Sander_
           _Pomatomus_ (_Cheilodipterus_) remains _Pomatomus_
           _Nomeus_ (_Gobiomorus_)        remains _Nomeus_
           _Galeus_ (_Galeorhinus_)       remains _Galeus_
           _Carcharias_ (_Carcharhinus_)  remains _Carcharias_

Footnote 1:

  For most of this list of errata I am indebted to the kindly interest
  of Dr. B. W. Evermann.



                               CHAPTER I
                              THE GANOIDS


=SUBCLASS Actinopteri.=—In our glance over the taxonomy of the earlier
Chordates, or fish-like vertebrates, we have detached from the main stem
one after another a long series of archaic or primitive types. We have
first set off those with rudimentary notochord, then those with
retrogressive development who lose the notochord, then those without
skull or brain, then those without limbs or lower jaw. The residue
assume the fish-like form of body, but still show great differences
among themselves. We have then detached those without membrane-bones, or
trace of lung or air-bladder. We next part company with those having the
air-bladder a veritable lung, and those with an ancient type of paired
fins, a jointed axis fringed with rays, and those having the palate
still forming the upper jaw. We have finally left only those having
fish-jaws, fish-fins, and in general the structure of the modern fish.
For all these in all their variety, as a class or subclass, the name
_Actinopteri_, or _Actinopterygii_, suggested by Professor Cope, is now
generally adopted. The shorter form, _Actinopteri_, being equally
correct is certainly preferable. This term (ακτίς, ray; πτερόν or
πτερύξ, fin) refers to the structure of the paired fins. In all these
fishes the bones supporting the fin-rays are highly specialized and at
the same time concealed by the general integument of the body. In
general two bones connect the pectoral fin with the shoulder-girdle. The
hypercoracoid is a flat square bone, usually perforated by a foramen.
Lying below it and parallel with it is the irregularly formed
hypocoracoid. Attached to them is a row of bones, the actinosts, or
pterygials, short, often hour-glass-shaped, which actually support the
fin-rays. In the more specialized forms, or Teleosts, the actinosts are
few (four to six) in number, but in the more primitive types, or
Ganoids, they may remain numerous, a reminiscence of the condition seen
in the Crossopterygians, and especially in _Polypterus_. Other
variations may occur; the two coracoids sometimes are imperfect or
specially modified, the upper sometimes without a foramen, and the
actinosts may be distorted in form or position.

[Illustration:

  FIG. 1.—Shoulder-girdle of a Flounder, _Paralichthys californicus_
    (Ayres).
]

=The Series Ganoidei.=—Among the lower _Actinopteri_ many archaic traits
still persist, and in its earlier representatives the group approaches
closely to the _Crossopterygii_, although no forms actually intermediate
are known either living or fossil. The great group of _Actinopteri_ may
be divided into two series or subclasses, the _Ganoidei_, or
_Chrondrostei_, containing those forms, mostly extinct, which retain
archaic traits of one sort or another, and the _Teleostei_, or bony
fishes, in which most of the primitive characters have disappeared.
Doubtless all of the _Teleostei_ are descended from a ganoid ancestry.

Even among the _Ganoidei_, as the term is here restricted, there remains
a very great variety of form and structure. The fossil and existing
forms do not form continuous series, but represent the tips and remains
of many diverging branches perhaps from some Crossopterygian central
stock. The group constitutes at least three distinct orders and, as a
whole, does not admit of perfect definition. In most but not all of the
species the tail is distinctly and obviously heterocercal, the lack of
symmetry of the tail in some Teleosts being confined to the bones and
not evident without dissection. Most of the Ganoids have the skeleton
still cartilaginous, and in some it remains in a very primitive
condition. Usually the Ganoids have an armature of bony plates,
diamond-shaped, with an enamel like that developed on the teeth. In all
of them the pectoral fin has numerous basal bones or actinosts. All of
them have the air-bladder highly developed, usually cellular and
functional as a lung, but connecting with the dorsal side of the gullet,
not with the ventral side as in the Dipnoans. In all living forms there
is a more or less perfect optic chiasma. These ancient forms retain also
the many valves of the arterial bulb and the spiral valve of the
intestines found in the more archaic types of fishes. But traces of some
or all of these structures are found in some bony fishes, and their
presence in the Ganoids by no means justifies the union of the Ganoids
with the sharks, Dipnoans, and Crossopterygians to form a great primary
class, _Palæichthyes_, as proposed by Dr. Günther. Almost every form of
body may be found among the Ganoids. In the Mesozoic seas these fishes
were scarcely less varied and perhaps scarcely less abundant than the
Teleosts in the seas of to-day. They far exceed the Crossopterygians in
number and variety of forms. Transitional forms connecting the two
groups are thus far not recognized. So far as fossils show, the
characteristic actinopterous fin with its reduced and altered basal
bones appeared at once without intervening gradations.

The name _Ganoidei_ (γάνος, brightness; εἶδος, resemblance), alluding to
the enameled plates, was first given by Agassiz to those forms, mostly
extinct, which were covered with bony scales or hard plates of one sort
or another. As the term was originally defined, mailed catfishes,
sea-horses, _Agonidæ_, _Arthrodires_, _Ostracophores_, and other wholly
unrelated types were included with the garpikes and sturgeons as
Ganoids. Most of these intruding forms among living fishes were
eliminated by Johannes Müller, who recognized the various archaic
characters common to the existing forms after the removal of the mailed
Teleosts. Still later Huxley separated the Crossopterygians as a
distinct group, while others have shown that the _Ostracophori_ and
_Arthrodira_ should be placed far from the garpike in systematic
classification. Cope, Woodward, Hay, and others have dropped the name
Ganoid altogether as productive of confusion through the many meanings
attached to it. Others have kept it as a convenient group name for the
orders of archaic _Actinopteri_. For these varied and more or less
divergent forms it seems convenient to retain it. As an adjective
"ganoid" is sometimes used as descriptive of bony plates or enameled
scales, some-in the sense of archaic, as applied to fishes.

=Are the Ganoids a Natural Group?=—Several writers have urged that the
_Ganoidei_, even as thus restricted, should not be considered as a
natural group, whether subclass, order, or group of orders. The reasons
for this view in brief are the following:

1. The group is heterogeneous. The _Amiidæ_ differ more from the other
Ganoids than they do from the herring-like Teleosts. The garpikes,
sturgeons, paddle-fishes likewise diverge widely from each other and
from the _Palæoniscidæ_ and the _Platysomidæ_. Each of the living
families represents the residue or culmination of a long series, in some
cases advancing, as in the case of the bowfin, sometimes perhaps
degenerating, as in the case of the sturgeons.

2. Of the traits possessed in common by these forms, several (the
cellular air-bladder, the many valves in the heart, the spiral valve in
the intestine, the heterocercal tail) are all possessed in greater or
less degree by certain _Isospondyli_ or allies of the herring. All these
characters are still better developed in _Crossoptergyii_ and
_Dipneusti_, and each one disappears by degrees. Of the characters drawn
from the soft parts we can know nothing so far as the extinct Ganoids
are concerned.

3. The optic chiasma, thus far characteristic of Ganoids as distinct
from Teleosts, may have no great value. It is urged that in closely
related species of lizards some have the optic chiasma and others do
not. This, however, proves nothing as to the value of the same character
among fishes.

4. The transition from Ganoids to Teleosts is of much the same character
as the transition from spiny-rayed to soft-rayed fishes, or that from
fishes with a duct to the air-bladder to those without such duct.

Admitting all this, it is nevertheless natural and convenient to retain
the Ganoidei (or _Chrondrostei_ if the older name be discarded on
account of the many meanings attached to it) as a group equivalent to
that of _Teleostei_ within the class or subclass of _Actinopteri_. It
comprises the transitional forms between the _Crossopterygii_ and the
bony fishes, and its members are especially characteristic of the
Mesozoic age, ranging from the Devonian to the present era.

Of the extensive discussion relating to this important question we may
quote two arguments for the retention of the subclass of Ganoids, the
first by Francis M. Balfour and William Kitchen Parker, the second from
the pen of Theodore Gill.

Balfour and Parker ("Structure and Development of Lepidosteus," pp.
430-433) thus discuss the

=Systematic Position of Lepidosteus.=—"Alexander Agassiz concludes his
memoir on the development of _Lepidosteus_ by pointing out that in spite
of certain affinities in other directions this form is 'not so far
removed from the bony fishes as has been supposed.' Our own observations
go far to confirm Agassiz's opinion.

"Apart from the complete segmentation, the general development of
_Lepidosteus_ is strikingly Teleostean. In addition to the general
Teleostean features of the embryo and larva, which can only be
appreciated by those who have had an opportunity of practically working
at the subject, we may point to the following developmental features[2]
as indicative of Teleostean affinities:

"(1) The formation of the nervous system as a solid keel of the
epiblast.

"(2) The division of the epiblast into a nervous and epidermic stratum.

"(3) The mode of development of the gut.

"(4) The mode of development of the pronephros; though the pronephros of
_Lepidosteus_ has primitive characters not retained by Teleostei.

"(5) The early stages in the development of the vertebral column.

Footnote 2:

  The features enumerated above are not in all cases confined to
  _Lepidosteus_ and Teleostei, but are always eminently characteristic
  of the latter.

"In addition to these, so to speak, purely embryonic characters there
are not a few important adult characters:

"(1) The continuity of the oviducts with the genital glands.

"(2) The small size of the pancreas, and the presence of numerous
so-called pancreatic cæca.

"(3) The somewhat coiled small intestine.

"(4) Certain characters of the brain, e.g., the large size of the
cerebellum; the presence of the so-called lobi inferiores on the
infundibulum, and of tori semi-circulares in the mid-brain.

"In spite of the undoubtedly important list of features to which we have
just called attention, a list containing not less important characters,
both embryological and adult, separating _Lepidosteus_ from the
Teleostei, can be drawn up:

"(1) The character of the truncus arteriosus.

"(2) The fact of the genital ducts joining the ureters.

"(3) The presence of vasa efferentia in the male carrying the semen from
the testes to the kidney, and through the tubules of the latter into the
kidney-duct.

"(4) The presence of a well-developed opercular gill.

"(5) The presence of a spiral valve; though this character may possibly
break down with the extension of our knowledge.

"(6) The typical Ganoid characters of the thalamencephalon and the
cerebral hemispheres.

"(7) The chiasma of the optic nerves.

"(8) The absence of a pecten, and presence of a vascular membrane
between the vitreous humor and the retina.

"(9) The opisthocœlous form of the vertebræ.

"(10) The articulation of the ventral parts of the hæmal arches of the
tail with the processes of the vertebral column.

"(11) The absence of a division of the muscles into dorso-lateral and
ventro-lateral divisions.

"(12) The complete segmentation of the ovum.

"The list just given appears to us sufficient to demonstrate that
Lepidosteus cannot be classed with the Teleostei; and we hold that
Müller's view is correct, according to which _Lepidosteus_ is a true
Ganoid.

"The existence of the Ganoids as a distinct group has, however, recently
been challenged by so distinguished an ichthyologist as Günther, and it
may therefore be well to consider how far the group as defined by Müller
is a natural one for living forms, and how far recent researches enable
us to improve upon Müller's definitions. In his classical memoir the
characters of the Ganoids are thus shortly stated:

"'These fishes are either provided with plate-like angular or rounded
cement-covered scales, or they bear osseous plates, or are quite naked.
The fins are often, but not always, beset with a double or single row of
spinous plates or splints. The caudal fin embraces occasionally in its
upper lobe the end of the vertebral column, which may be prolonged to
the end of the upper lobe. Their double nasal openings resemble those of
Teleostei. The gills are free, and lie in a branchial cavity under an
operculum, like those of Teleostei. Many of them have an accessory organ
of respiration, in the form of an opercular gill, which is distinct from
the pseudobranch, and can be present together with the latter; many also
have spiracles like Elasmobranchii. They have many valves in the stem of
the aorta like the latter, also a muscular coat in the stem of the
aorta. Their ova are transported from the abdominal cavity by oviducts.
Their optic nerves do not cross each other. The intestine is often
provided with a spiral valve, like Elasmobranchii. They have a
swimming-bladder with a duct, like many Teleostei. Their pelvic fins are
abdominal.

"'If we include in a definition only those characters which are
invariable, the Ganoids may be shortly defined as being those fish with
numerous valves to the stem of the aorta, which is also provided with a
muscular coat, with free gills, and an operculum, and with abdominal
pelvic fins.'

"To these distinctive characters he adds, in an appendix to his paper,
the presence of the spiral valve, and the absence of a processus
falciformis and a choroid gland.

"To the distinctive set of characters given by Müller we may probably
add the following:

"(1) Oviducts and urinary ducts always unite, and open by a common
urogenital aperture behind the anus.

"(2) Skull hyostylic.

"(3) Segmentation complete in the types so far investigated, though
perhaps _Amia_ may be found to resemble the Teleostei in this
particular.

"(4) A pronephros of the Teleostean type present in the larva.

"(5) Thalamencephalon very large and well developed.

"(6) The ventricle in the posterior part of the cerebrum is not divided
behind into lateral halves, the roof of the undivided part being
extremely thin.

"(7) Abdominal pores always present.

"The great number of characters just given are amply sufficient to
differentiate the Ganoids as a group; but, curiously enough, the only
characters, amongst the whole series which have been given, which can be
regarded as peculiar to the Ganoids are (1) the characters of the brain,
and (2) the fact of the oviducts and kidney-ducts uniting together and
opening by a common pore to the exterior.

"This absence of characters peculiar to the Ganoids is an indication of
how widely separated in organization are the different members of this
great group.

"At the same time, the only group with which existing Ganoids have close
affinities is the Teleostei. The points they have in common with the
Elasmobranchii are merely such as are due to the fact that both retain
numerous primitive vertebrate characters,[3] and the gulf which really
separates them is very wide.

Footnote 3:

  As instances of this we may cite (1) the spiral valve; (2) the
  frequent presence of a spiracle; (3) the frequent presence of a
  communication between the pericardium and the body-cavity; (4) the
  heterocercal tail.

"There is again no indication of any close affinity between the Dipnoans
and, at any rate, existing Ganoids.

"Like the Ganoids, the Dipnoans are no doubt remnants of a very
primitive stock; but in the conversion of the air-bladder into a true
lung, the highly specialized character of their limbs,[4] their peculiar
autostylic skulls, the fact of their ventral nasal openings leading
directly into the mouth, their multi-segmented bars (interspinous bars)
directly prolonged from the neural and hæmal and supporting the fin-rays
of the unpaired dorsal and ventral fins, and their well-developed
cerebral hemispheres, very unlike those of Ganoids and approaching the
Amphibian type, they form a very well-defined group and one very
distinctly separated from the Ganoids.

Footnote 4:

  Vide F. M. Balfour, "On the Development of the Skeleton of the Paired
  Fins of Elasmobranchs," Proc. Zool. Soc., 1881.

"No doubt the Chondrostean Ganoids are nearly as far removed from the
Teleostei as from the Dipnoans, but the links uniting these Ganoids with
the Teleostei have been so fully preserved in the existing fauna of the
globe that the two groups almost run into each other. If, in fact, we
were anxious to make any radical change in the ordinary classification
of fishes, it would be by uniting the Teleostei and Ganoids, or rather
constituting the Teleostei into one of the subgroups of the Ganoids,
equivalent to the Chondrostei. We do not recommend such an arrangement,
which in view of the great preponderance of the Teleostei amongst living
fishes would be highly inconvenient, but the step from _Amia_ to the
Teleostei is certainly not so great as that from the Chondrostei to
Amia, and is undoubtedly less than that from the Selachii to the
Holocephali."

=Gill on the Ganoids as a Natural Group.=—Dr. Gill observes ("Families
of Fishes," 1872): "The name Ganoides (or Ganiolepedoti) was originally
framed by Prof. Agassiz as an ordinal term for fishes having the scales
(when present) angular and covered with enamel; and in the group so
characterized were combined the Ganoids of subsequent authors as well as
the Teleostean orders Plectognathi, Lophobranchii, and Nematognathi, and
(subsequently) the genus _Sudis_ (_Arapaima_), the last being regarded
as a Cœlacanth. The group has not been accepted with these limits or
characters.

"But the researches of Prof. Johannes Müller on the anatomy and
classification of the fishes culminated at length in his celebrated
memoirs on those fishes for which he retained the ordinal name Ganoidei;
those memoirs have left an impression on ichthyology perhaps more
decided than made by any other contributions to science, and that
published _in extenso_ will ever be classical; numerous as have been the
modifications since introduced into the system, no forms except those
recognized by Müller (unless it be Dipnoi) have been interjected since
among the Ganoids.

"It has been objected that the Ganoids do not constitute a natural
group, and that the characters (i.e., chiasma of optic nerves and
multivalvular bulbus arteriosus) alleged by Müller to be peculiar to the
teleostomous forms combined therein are problematical, and only
_inferentially_ supposed to be common to the extinct Ganoids so called,
and, finally, such objections couched in too strong language have
culminated in the assertion that the characters in question are actually
_shared_ by other physostome fishes.

"No _demonstration_, however, has been presented as yet that any
physostome fishes do really have the optic chiasma and multivalvular
_bulbus arteriosus_, and the statement to the contrary seems to have
been the result of a venial misapprehension of Prof. Kner's statements,
or the offspring of impressions left on the memory by his assertions, in
forgetfulness of his exact words.

"But Prof. Kner, in respect to the anatomical characters referred to,
merely objects: (1) that they are _problematical_, are not confirmable
for the extinct types, and were _probably_ not existent in certain forms
that have been referred to the Ganoids; (2) the difference in number of
the valves of the _bulbus arteriosus_ among recent Ganoids is so great
as to show the unreliability of the character; (3) a spiral valve is
developed in the intestine of several osseous fishes ('genera of the
so-called intermediate clupeoid groups'), as well as in Ganoids; and (4)
the chiasma of the optic nerves in no wise furnishes a positive
character for the Ganoids.

"It will be noticed that all these objections (save in the case of the
intestinal spiral valve) are hypothetical and vague. The failure of the
intestinal spiral valve, as a diagnostic character, has long been
conceded, and in this case only have the forms that _prove_ the failure
been referred to; in the other cases, where it would be especially
desirable to have indicated the actual types falsifying the universality
or exclusiveness of the characters, they have not been referred to, and
the objections must be met as if they were not known to exist.

"(1) The characters in question are, in the sense used, problematical,
inasmuch as no examination can be made of the soft parts of extinct
forms, but with equal force may it be urged that any characters that
have not been or cannot be _directly_ confirmed are problematical in the
case of all other groups (e.g., mammals), and it can only be replied
that the coordination of parts has been so invariably verified that all
probabilities are in favor of similar coordination in any given case.

"(2) There is doubtless considerable difference in the number of valves
of the _bulbus arteriosus_ among the various Ganoids, and even among the
species of a single family (e.g., _Lepidosteidæ_), but the character of
Ganoids lies not in the number, more or less, but in the greater number
and relations (in contradistinction to the opposite pair of the
Teleosts) in conjunction with the development of a _bulbus arteriosus_.
In no other forms of Teleostomes have similar relations and structures
been yet demonstrated.

"(3) The failure of the spiral intestinal valve has already been
conceded, and no great stress has ever been laid on the character.

"(4) The chiasma of the optic nerves is so common to all the known
Ganoids, and has not been found in those forms (e.g., _Arapaima_,
_Osteoglossum_, and _Clupeiform_ types) agreeing with typical physostome
Teleosts in the skeleton, heart, etc., but which at the same time
simulate most certain Ganoids (e.g., _Amia_) in form.

"Therefore, in view of the evidence hitherto obtained, the arguments
against the validity of title, to natural association, of the Ganoids,
have to meet the positive evidence of the coordinations noted; the value
of such characteristics and coordinations can only be affected or
destroyed by the demonstration that in all other respects there is (1)
very close agreement of certain of the constituents of the subclass with
other forms, and (2) inversely proportionate dissimilarity of those
forms from _any_ (not all) other of the Ganoids, and consequently
evidence _ubi plurima nitent_ against the taxonomic value of the
characters employed for distinction.

"And it is true that there is a greater superficial resemblance between
the Hyoganoids (_Lepisosteus_, _Amia_, etc.) and ordinary physostome
Teleosts than between the former and the other orders of Ganoids, but it
is equally true that they agree in other respects than in the brain and
heart with the more generalized Ganoids. They all have, for example, (1)
the paraglenal elements undivided (not disintegrated into hypercoracoid,
hypocoracoid, and mesocoracoid); (2) a humerus (simple or divided, that
is, differentiated into metapterygium and mesopterygium); and (3) those
with ossified skeletons agree in the greater number of elements in the
lower jaw. Therefore, until these coordinates fail, it seems advisable
to recognize the Ganoids as constituents of a natural series; and
especially on account of the superior taxonomic value of modifications
of the brain and heart in other classes of vertebrates, for the same
reason, and to keep prominently before the mind the characters in
question, it appears also advisable to designate the series, until
further discovery, as a subclass.

"But it is quite possible that among some of the generalized Teleosts at
least _traces_ of some of the characters now considered to be peculiar
to the Ganoids may be discovered. In anticipation of such a possibility,
the author had at first discarded the subclass, recognizing the group
only as one of the 'superorders' of the Teleostomes, but reconsideration
convinces him of the propriety of classification representing known
facts and legitimate inferences rather than too much anticipation.

"It is remembered that all characters are liable to fail with increasing
knowledge, and the distinctness of groups are but little more than the
expressions of our want of knowledge of the intermediate forms; it may
in truth be said that ability to segregate a class into well-defined
groups is in ratio to our ignorance of all the terms."



                               CHAPTER II
                         THE GANOIDS—Continued


=CLASSIFICATION of Ganoids.=—The subdivision of the series of Ganoidei
into orders offers great difficulty from the fact of the varying
relationships of the members of the group and the fact that the great
majority of the species are known only from broken skeletons preserved
in the rocks. It is apparently easy to separate those with cartilaginous
skeletons from those with these bones more or less ossified. It is also
easy to separate those with bony scales or plates from those having the
scales cycloid. But the one type of skeleton grades into the other, and
there is a bony basis even to the thinnest of scales found in this
group. Among the multitude of names and divisions proposed we may
recognize six orders, for which the names _Lysopteri_, _Chondrostei_,
_Selachostomi_, _Pycnodonti_, _Lepidostei_, and _Halecomorphi_ are not
inappropriate. Each of these seems to represent a distinct offshoot from
the first primitive group.

=Order Lysopteri.=—In the most primitive order, called _Lysopteri_
(λυσός, loose; πτερόν, fin) by Cope, _Heterocerci_ by Zittel and
Eastman, and the "ascending series of Chondrostei" by Woodward, we find
the nearest approach to the Chondropterygians. In this order the arches
of the vertebræ are more or less ossified, the body is more or less
short and deep, covered with bony dermal plates. The opercular apparatus
is well developed, with numerous branchiostegals. Infraclavicles are
present, and the fins provided with fulcra. Dorsal and anal fins are
present, with rays more numerous than their supports; ventral fin with
basal supports which are imperfectly ossified; caudal fin mostly
heterocercal, the scales mostly rhombic in form. All the members of this
group are now extinct.

=The Palæoniscidæ.=—The numerous genera of this order are referred to
three families, the _Palæoniscidæ_, _Platysomidæ_, and _Dictyopygidæ_; a
fourth family, _Dorypteridæ_, of uncertain relations, being also
tentatively recognized. The family of _Palæoniscidæ_ is the most
primitive, ranging from the Devonian to the Lias, and some of them seem
to have entered fresh waters in the time of the coal-measures. These
fishes have the body elongate and provided with one short dorsal fin.
The tail is heterocercal and the body covered with rhombic plates.
Fulcra or rudimentary spine-like scales are developed on the upper edge
of the caudal fin in most recent Ganoids, and often the back has a
median row of undeveloped scales. A multitude of species and genera are
recorded. A typical form is the genus _Palæoniscum_,[5] with many
species represented in the rocks of various parts of the world. The
longest known species is _Palæoniscum frieslebenense_ from the Permian
of Germany and England. _Palæoniscum magnum_, sixteen inches long,
occurs in the Permian of Germany. From _Canobius_, the most primitive
genus, to _Coccolepis_, the most modern, is a continuous series, the
suspensorium of the lower jaw becoming more oblique, the basal bones of
the dorsal fewer, the dorsal extending farther forward, and the scales
more completely imbricate. Other prominent genera are _Amblypterus_,
_Eurylepis_, _Cheirolepis_, _Rhadinichthys_, _Pygopterus_,
_Elonichthys_, _Ærolepis_, _Gyrolepis_, _Myriolepis_, _Oxygnathus_,
_Centrolepis_, and _Holurus_.

Footnote 5:

  This word is usually written _Palæoniscus_, but Blainville, its author
  (1818), chose the neuter form.

[Illustration:

  FIG. 2.—_Palæoniscum frieslebenense_ Blainville. Family
    _Palæoniscidæ_. (After Zittel.)
]

=The Platysomidæ.=—The _Platysomidæ_ are different in form, the body
being deep and compressed, often diamond-shaped, with very long dorsal
and anal fins. In other respects they are very similar to the
_Palæoniscidæ_, the osteology being the same. The _Palæoniscidæ_ were
rapacious fishes with sharp teeth, the _Platysomidæ_ less active, and,
from the blunter teeth, probably feeding on small animals, as crabs and
snails.

The rhombic enameled scales are highly specialized and held together as
a coat of mail by peg-and-socket joints. The most extreme form is
_Platysomus_, with the body very deep. _Platysomus gibbosus_ and other
species occur in the Permian rocks of Germany. _Cheirodus_ is similar to
_Platysomus_, but without ventral fins. _Eurynotus_, the most primitive
genus, is remarkable for its large pectoral fins. _Eurynotus crenatus_
occurs in the Subcarboniferous of Scotland. Other genera are
_Mesolepis_, _Globulodus_, _Wardichthys_, and _Cheirodopsis_.

[Illustration:

  FIG. 3.—_Eurynotus crenatus_ Agassiz, restored. Carboniferous. Family
    _Platysomidæ_. (After Traquair.)
]

Some of the _Platysomidæ_ have the interneural spines projecting through
the skin before the dorsal fin. This condition is found also in certain
bony fishes allied to the _Carangidæ_.

=The Dorypteridæ.=—_Dorypterus hoffmani_, the type of the singular
Palæozoic family of _Dorypteridæ_, with thoracic or sub-jugular
many-rayed ventrals, is Stromateus-like to all appearance, with distinct
resemblances to certain Scombroid forms, but with a heterocercal tail
like a ganoid, imperfectly ossified back-bone, and other very archaic
characters. The body is apparently scaleless, unlike the true
_Platysomidæ_, in which the scales are highly developed. A second
species, _Dorypterus althausi_, also from the German copper shales, has
been described. This species has lower fins than _Dorypterus hoffmani_,
but may be the adult of the same type. _Dorypterus_ is regarded by
Woodward as a specialized offshoot from the _Platysomidæ_. The
many-rayed ventrals and the general form of the body and fins suggest
affinity with the _Lampridæ_.

[Illustration:

  FIG. 4.—_Dorypterus hoffmani_ Germar, restored. (After Hancock and
    Howse.)
]

=Dictyopygidæ.=—In the _Dictyopygidæ_ (_Catopteridæ_), the body is
gracefully elongate, less compressed, the heterocercal tail is short and
abruptly turned upwards, the teeth are sharp and usually hooked, and the
bony plates well developed. Of this group two genera are recognized,
each containing numerous species. In _Redfieldius_ (= _Catopterus_
Redfield, not of Agassiz) the dorsal is inserted behind the anal, while
in _Dictyopyge_ this is not the case. _Redfieldius gracilis_ and other
species are found in the Triassic of the Connecticut River. _Dictyopyge
macrura_ is found in the same region, and _Dictyopyge catoptera_ and
other species in Europe.

=Order Chondrostei.=—The order _Chondrostei_ (χόνδρος, cartilage;
ὀστέον, bone), as accepted by Woodward, is characterized by the
persistence of the notochord in greater or less degree, the endoskeleton
remaining cartilaginous. In all, the axonosts and baseosts of the median
fins are arranged in simple regular series and the rays are more
numerous than the supporting elements. The shoulder-girdle has a pair of
infraclavicular plates. The pelvic fins have well-developed baseosts.
The branchiostegals are few or wanting. In the living forms, and
probably in all others, a matter which can never be ascertained, the
optic nerves are not decussating, but form an optic chiasma, and the
intestine is provided with a spiral valve. In all the species there is
one dorsal and one anal fin, separate from the caudal. The teeth are
small or wanting, the body naked or covered with bony plates; the caudal
fin is usually heterocercal, and on the tail are rhombic plates. To this
order, as thus defined, about half of the extinct Ganoids belong, as
well as the modern degenerate forms known as sturgeons and perhaps the
paddle-fishes, which are apparently derived from fishes with rhombic
enameled scales. The species extend from the Upper Carboniferous to the
present time, being most numerous in the Triassic.

At this point in Woodward's system diverges a descending series,
characterized as a whole by imperfect squamation and elongate form, this
leading through the synthetic type of _Chondrosteidæ_ to the modern
sturgeon and paddle-fish, which are regarded as degenerate types.

The family of _Saurorhynchidæ_ contains pike-like forms, with long jaws,
and long conical teeth set wide apart. The tail is not heterocercal, but
short-diphycercal; the bones of the head are covered with enamel, and
those of the roof of the skull form a continuous shield. The opercular
apparatus is much reduced, and there are no branchiostegals. The fins
are all small, without fulcra, and the skin has isolated longitudinal
series of bony scutes, but is not covered with continuous scales. The
principal genus is _Saurorhynchus_ (= _Belonorhynchus_; the former being
the earlier name) from the Triassic. _Saurorhynchus acutus_ from the
English Triassic is the best known species.

The family of _Chondrosteidæ_ includes the Triassic precursors of the
sturgeons. The general form is that of the sturgeon, but the body is
scaleless except on the upper caudal lobe, and there are no plates on
the median line of the skull. The opercle and subopercle are present,
the jaws are toothless, and there are a few well-developed caudal rays.
The caudal has large fulcra. The single well-known species of this
group, _Chondrosteus acipenseroides_, is found in the Triassic rocks of
England and reaches a length of about three feet. It much resembles a
modern sturgeon, though differing in several technical respects.
_Chondrosteus pachyurus_ is based on the tail of a species of much
larger size and _Gyrosteus mirabilis_, also of the English Triassic, is
known from fragments of fishes which must have been 18 to 20 feet in
length.

[Illustration:

  FIG. 5.—_Chondrosteus acipenseroides_ Egerton. Family _Chondrosteidæ_.
    (After Woodward.)
]

The sturgeons constitute the recent family of _Acipenseridæ_,
characterized by the prolonged snout and toothless jaws and the presence
of four barbels below the snout. In the _Acipenseridæ_ there are no
branchiostegals and a median series of plates is present on the head.
The body is armed with five rows of large bony bucklers,—each often with
a hooked spine, sharpest in the young. Besides these, rhombic plates are
developed on the tail, besides large fulcra. The sturgeons are the
youngest of the Ganoids, not occurring before the Lower Eocene, one
species, _Acipenser toliapicus_ occurring in the London clay. About
thirty living species of sturgeon are known, referred to three genera:
_Acipenser_, found throughout the Northern Hemisphere, _Scaphirhynchus_,
in the Mississippi Valley, and _Kessleria_ (later called
_Pseudoscaphirhynchus_), in Central Asia alone. Most of the species
belong to the genus _Acipenser_, which abounds in all the rivers and
seas in which salmon are found. Some of the smaller species spend their
lives in the rivers, ascending smaller streams to spawn. Other sturgeons
are marine, ascending fresh waters only for a moderate distance in the
spawning season. They range in length from 2½ to 30 feet.

All are used as food, although the flesh is rather coarse and beefy.
From their large size and abundance they possess great economic value.
The eggs of some species are prepared as caviar.

[Illustration:

  FIG. 6.—Common Sturgeon, _Acipenser sturio_ Mitchill. Potomac River.
]

The sturgeons are sluggish, clumsy, bottom-feeding fish. The mouth,
underneath the long snout, is very protractile, sucker-like, and without
teeth. Before it on the under side of the snout are four long feelers.
Ordinarily the sturgeon feeds on mud and snails with other small
creatures, but I have seen large numbers of Eulachon (_Thaleichthys_) in
the stomach of the Columbia River sturgeon (_Acipenser transmontanus_).
This fish and the Eulachon run in the Columbia at the same time, and the
sucker-mouth of a large sturgeon will draw into it numbers of small
fishes who may be unsuspiciously engaged in depositing their spawn. In
the spawning season in June these clumsy fishes will often leap wholly
out of the water in their play. The sturgeons have a rough skin besides
five series of bony plates which change much with age and which in very
old examples are sometimes lost or absorbed in the skin. The common
sturgeon of the Atlantic on both shores is _Acipenser sturio_.
_Acipenser huso_ and numerous other species are found in Russia and
Siberia. The great sturgeon of the Columbia is _Acipenser
transmontanus_, and the great sturgeon of Japan _Acipenser kikuchii_.
Smaller species are found farther south, as in the Mediterranean and
along the Carolina coast. Other small species abound in rivers and
lakes. _Acipenser rubicundus_ is found throughout the Great Lake region
and the Mississippi Valley, never entering the sea. It is four to six
feet long, and at Sandusky, Ohio, in one season 14,000 sturgeons were
taken in the pound nets. A similar species, _Acipenser mikadoi_, is
abundant and valuable in the streams of northern Japan.

[Illustration:

  FIG. 7.—Lake Sturgeon, _Acipenser rubicundus_ Le Sueur. Ecorse, Mich.
]

In the genus _Acipenser_ the snout is sharp and conical, and the
shark-like spiracle is still retained.

[Illustration:

  FIG. 8.—Shovel-nosed Sturgeon. _Scaphirhynchus platyrhynchus_
    (Rafinesque). Ohio River.
]

The shovel-nosed sturgeon (_Scaphirhynchus platyrhynchus_) has lost the
spiracles, the tail is more slender, its surface wholly bony, and the
snout is broad and shaped like a shovel. The single species of
_Scaphirhynchus_ abounds in the Mississippi Valley, a fish more
interesting to the naturalist than to the fisherman. It is the smallest
of our sturgeons, often taken in the nets in large numbers.

In _Scaphirhynchus_ the tail is covered by a continuous coat of mail. In
_Kessleria[6] fedtschenkoi_, _rossikowi_, and other Asiatic species the
tail is not mailed.

Footnote 6:

  These species have also been named _Pseudoscaphirhynchus_. _Kessleria_
  is the earlier name, left undefined by its describer, although the
  type was indicated.

=Order Selachostomi: the Paddle-fishes.=—Another type of Ganoids, allied
to the sturgeons, perhaps still further degenerate, is that of the
paddle-fishes, called by Cope _Selachostomi_ (σέλαχος, shark; στόμα,
mouth). This group consists of a single family, _Polyodontidæ_, having
apparently little in common with the other Ganoids, and in appearance
still more suggestive of the sharks. The common name of paddle-fishes is
derived from the long flat blade in which the snout terminates. This
extends far beyond the mouth, is more or less sensitive, and is used to
stir up the mud in which are found the minute organisms on which the
fish feeds. Under the paddle are four very minute barbels corresponding
to those of the sturgeons. The vernacular names of spoonbill, duckbill
cat, and shovel-fish are also derived from the form of the snout. The
skin is nearly smooth, the tail is heterocercal, the teeth are very
small, and a long fleshy flap covers the gill-opening. The very long and
slender gill-rakers serve to strain the food (worms, leeches,
water-beetles, crustaceans, and algæ) from the muddy waters from which
they are taken. The most important part of this diet consists of
Entomostracans. The single American species, _Polyodon spathula_,
abounds through the Mississippi Valley in all the larger streams. It
reaches a length of three or four feet. It is often taken in the nets,
but the coarse tough flesh, like that of our inferior catfish, is not
much esteemed. In the great rivers of China, the Yangtse and the Hoang
Ho, is a second species, _Psephurus gladius_, with narrower snout, fewer
gill-rakers, and much coarser fulcra on the tail. The habits, so far as
known, are much the same.

[Illustration:

  FIG. 9.—Paddle-fish, _Polyodon spathula_ (Walbaum). Ohio River.
]

[Illustration:

  FIG. 10.—Paddle-fish. _Polyodon Spathula_ (Walbaum). Ohio River.
]

[Illustration:

  FIG. 11.—_Psephurus gladius_ Günther. Yangtse River. (After Günther.)
]

_Crossopholis magnicaudatus_ of the Green River Eocene shales is a
primitive member of the _Polyodontidæ_. Its rostral blade is shorter
than that of _Polyodon_, and the body is covered with small thin scales,
each in the form of a small grooved disk with several posterior
denticulations, arranged in oblique series but not in contact. The
scales are quadrate in form, and more widely separated anteriorly than
posteriorly. As in _Polyodon_, the teeth are minute and there are no
branchiostegals. The squamation of this fish shows that _Polyodon_ as
well as _Acipenser_ may have sprung from a type having rhombic scales.
The tail of a Cretaceous fish, _Pholidurus disjectus_ from the
Cretaceous of Europe, has been referred with doubt to this family of
_Polyodontidæ_.

=Order Pycnodonti.=—In the extinct order _Pycnodonti_, as recognized by
Dr. O. P. Hay, the notochord is persistent and without ossification, the
body is very deep, the teeth are always blunt, the opercular apparatus
is reduced, the dorsal fin many-rayed, and the fins without fulcra. The
scales are rhombic, but are sometimes wanting, at least on the tail.
Many genera and species of _Pycnodontidæ_ are described, mostly from
Triassic and Jurassic rocks of Europe. Leading European genera are
_Pycnodus_, _Typodus_ (_Mesodon_), _Gyrodus_, and _Palæobalistum_. The
numerous American species belong to _Typodus_, _Cœlodus_, _Pycnodus_,
_Hadrodus_, and _Uranoplosus_. These forms have no affinity with
_Balistes_, although there is some resemblance in appearance, which has
suggested the name of _Palæobalistum_.

[Illustration:

  FIG. 12.—_Gyrodus hexagonus_ Agassiz. Family _Pycnodontidæ_.
    Lithographic Shales.
]

Woodward places these fishes with the _Semionotidæ_ and _Halecomorphi_
in his suborder of _Protospondyli_. It seems preferable, however, to
consider them as forming a distinct order.

[Illustration:

  FIG. 13.—_Mesturus verrucosus_ Wagner. Family _Pycnodontidæ_. (After
    Woodward.)
]

=Order Lepidostei.=—We may place, following Eastman's edition of Zittel,
the allies and predecessors of the garpike in a single order, for which
Huxley's name _Lepidostei_ may well be used. In this group the notochord
is persistent, and the vertebræ are in various degrees of ossification
and of different forms. The opercles are usually complete, the
branchiostegals present, and there is often a gular plate. There is no
infraclavicle and the jaws have sharp teeth. The fins have fulcra, and
the supports of the fins agree in number with the rays. The tail is more
or less heterocercal. The scales are rhombic, arranged in oblique
series, which are often united above and below with peg-and-socket
articulations. This group contains among recent fishes only the garpikes
(_Lepisosteus_). They are closely allied to the _Palæoniscidæ_, but the
skeleton is more highly ossified. On the other hand they approach very
closely to the ancestors of the bowfin, _Amia_. One genus,
_Acentrophorus_, appears in the Permian; the others are scattered
through Mesozoic and Tertiary rocks, the isolated group of gars still
persisting. In the gars the vertebræ are concavo-convex, with
ball-and-socket joints. In the others the vertebræ are incomplete or
else double-concave, as in fishes generally.

For the group here called _Lepidostei_ numerous other names have been
used corresponding wholly or in part. _Rhomboganoidea_ of Gill covers
nearly the same groups; _Holostei_ of Müller and _Hyoganoidea_ of Gill
include the _Halecomorphi_ also; _Ginglymodi_ of Cope includes the
garpikes only, while _Ætheospondyli_ of Woodward includes the
_Aspidorhynchidæ_ and the garpikes.

[Illustration:

  FIG. 14.—_Semionotus kapffi_ Fraas, restored. Family _Semionotidæ_.
    (After Fraas, per Nicholson.)
]

The _Semionotidæ_ (_Stylodontidæ_) are robust-bodied Ganoids, having the
vertebræ developed as rings, the jaws with several rows of teeth, those
of the outer row styliform.

_Semionotus bergeri_ is a well-known species, with the body moderately
elongate. _Semionotus agassizi_ and many other species occur in the
Triassic of the Connecticut valley and in New Jersey. The body is very
deep in the related genus _Dapedium_, and the head is covered with
strong bony plates. _Dapedium politum_ is a well-known species of the
English Triassic. _Tetragonolepis_ (_Pleurolepis_) is a similar form,
very deep and compressed, with strong, firm scales.

In the extinct family of _Lepidotidæ_ the teeth are conical or
chisel-shaped, while blunt or molar teeth are on the inside of the
mouth, which is small, and the suspensorium of the mandible is vertical
or inclined forward. The body is robust-fusiform, covered with rhomboid
scales; the vertebræ form rings about the notochord; the teeth are
either sharp or blunt. The dorsal fin is short, with large fulcra.

The best known of the numerous genera are _Lepidotes_, rather elongate
in body, with large, blunt teeth. Of the many species of _Lepidotes_,
_Lepidotes elvensis_ abounds in the English and German Triassic, and
_Lepidotes minor_ in the English Triassic. Another well-known European
species is _Lepidotes mantelli_.

[Illustration:

  FIG. 15.—_Dapedium politum_ Leach, restored. Family _Semionotidæ_.
    (After Woodward.)
]

The _Isopholidæ_ (_Eugnathidæ_) differ from the families last named in
the large pike-like mouth with strong teeth. The mandibular suspensorium
is inclined backwards. The body is elongate, the vertebræ forming
incomplete rings; the dorsal fin is short with large fulcra.

_Isopholis dentosus_ is found with numerous other species in the British
Triassic. _Caturus furcatus_ is especially characteristic of Triassic
rocks in Germany. _Ptycholepis marshi_ occurs in the Connecticut valley.

[Illustration:

  FIG. 16.—_Tetragonolepis semicinctus_ Brown. Lias. Family
    _Semionotidæ_. (After Woodward.)
]

The _Macrosemiidæ_ are elongate fishes with long dorsal fin, the
numerous species being found in the Triassic, Jurassic, and Cretaceous
of Europe. _Macrosemius rostratus_ has a very high, continuous dorsal.
_Macropistius arenatus_ is found in the Cretaceous of Texas, the only
American species known. Prominent European genera are _Notagogus_,
_Ophiopsis_, and _Petalopteryx_.

[Illustration:

  FIG. 17.—_Isopholis orthostomus_ (Agassiz). Lias. (After Woodward.)
]

[Illustration:

  FIG. 18.—The Long-nosed Garpike, _Lepisosteus osseus_ (Linnæus). Fox
    River, Wisconsin. (From nature; D. S. Jordan and M. L. McDonald,
    1874.)
]

Intermediate between the allies of the gars and the modern herrings is
the large extinct family of _Pholidophoridæ_, referred by Woodward to
the _Isospondyli_, and by Eastman to the _Lepidostei_. These are small
fishes, fusiform in shape, chiefly of the Triassic and Jurassic. The
fins are fringed with fulcra, the scales are ganoid and rhombic, and the
vertebræ reduced to rings. The mouth is large, with small teeth, and
formed as in the _Isospondyli_. The caudal is scarcely heterocercal.

[Illustration:

  FIG. 19.—_Caturus elongatus_ Agassiz. Jurassic. Family _Isopholidæ_.
    (After Zittel.)
]

[Illustration:

  FIG. 20.—_Notagogus pentlandi_ Agassiz. Jurassic. Family
    _Macrosemiidæ_. (After Woodward.)
]

[Illustration:

  FIG. 21.—_Ptycholepis curtus_ Egerton. Lias. Family _Isopholidæ_.
    (After Woodward.)
]

Of _Pholidophorus_, with scales joined by peg-and-socket joints and
uniform in size, there are many species. _Pholidophorus latiusculus_ and
many others are found in the Triassic of England and the Continent.
_Pholidophorus americanus_ occurs in the Jurassic of South Dakota.
_Pleuropholis_, with the scales on the lateral line, which runs very
low, excessively deepened, is also widely distributed. I have before me
a new species from the Cretaceous rocks near Los Angeles. The
_Archæomænidæ_ differ from _Pholidophoridæ_ in having cycloid scales. In
both families the vertebræ are reduced to rings about the notochord.
From fishes allied to the _Pholidophoridæ_ the earliest _Isospondyli_
are probably descended.

[Illustration:

  FIG. 22.—_Pholidophorus crenulatus_ Egerton. Lias. (After Woodward.)
]

In the _Aspidorhynchidæ_ the snout is more or less produced, the
mandible has a distinct presymphysial bone, the vertebræ are
double-concave or ring-like, and the fins are without fulcra. This
family constitutes the suborder _Ætheospondyli_. In form these fishes
resemble _Albula_ and other modern types, but have mailed heads and an
ancient type of scales. Two genera are well known, _Aspidorhynchus_ and
_Belonostomus_. _Aspidorhynchus acutirostris_ reaches a length of three
feet, and is found in the Triassic lithographic stone of Bavaria. Other
species occur in rocks of Germany and England.

_Belonostomus_ has the snout scarcely produced. _Belonostomus
sphyrænoides_ is the best known of the numerous species, all of the
Triassic, Jurassic, and Cretaceous.

=Family Lepisosteidæ.=—The family of _Lepisosteidæ_, constituting the
suborder _Ginglymodi_ (γιγγλυμός, hinge), is characterized especially by
the form of the vertebræ.

These are opisthocœlian, convex in front and concave behind, as in
reptiles, being connected by ball-and-socket joints. The tail is
moderately heterocercal, less so than in the _Halecomorphi_, and the
body is covered with very hard, diamond-shaped, enameled scales in
structure similar to that of the teeth. A number of peculiar characters
are shown by these fishes, some of them having often been regarded as
reptilian traits. Notable features are the elongate, crocodile-like
jaws, the upper the longer, and both armed with strong teeth. The
mandible is without presymphysial bone. The fins are small with large
fulcra, and the scales are nearly uniform in size.

All the species belong to a single family, _Lepisosteidæ_, which
includes the modern garpikes and their immediate relatives, some of
which occur in the early Tertiary. These voracious fishes are
characterized by long and slender cylindrical bodies, with enameled
scales and mailed heads and heterocercal tail. The teeth are sharp and
unequal. The skeleton is well ossified, and the animal itself is
extremely voracious. The vertebræ, reptile-like, are opisthocœlian, that
is, convex in front, concave behind, forming ball-and-socket joints. In
almost all other fishes they are amphicœlian or double-concave, the
interspace filled with gelatinous substance. The recent species, and
perhaps all the extinct species also, belong to the single genus
_Lepisosteus_ (more correctly, but also more recently, spelled
_Lepidosteus_). Of existing forms there are not many species, three to
five at the most, and they swarm in the lakes, bayous, and sluggish
streams from Lake Champlain to Cuba and along the coast to Central
America. The best known of the species is the long-nosed garpike,
_Lepisosteus osseus_, which is found throughout most of the Great Lake
region and the Mississippi Valley, and in which the long and slender
jaws are much longer than the rest of the head. The garpike frequents
quiet waters and is apparently of sleepy habit. It often lies quiet for
a long time, carried around and around by the eddies. It does not
readily take the hook and seldom feeds in the aquarium. It feeds on
crayfishes and small fishes, to which it is exceedingly destructive, as
its bad reputation indicates. Fishermen everywhere destroy it without
mercy. Its flesh is rank and tough and unfit even for dogs.

In the young garpike the caudal fin appears as a second dorsal and anal,
the filamentous tip of the tail passing through and beyond it.

The short-nosed garpike, _Lepisosteus platystomus_, is generally common
throughout the Mississippi Valley. It has a short broad snout like the
alligator-gar, but seldom exceeds three feet in length. In size, color,
and habits it agrees closely with the common gar, differing only in the
form of the snout. The form is subject to much variation, and it is
possible that two or more species have been confounded.

[Illustration:

  FIG. 23.—Alligator-gar, _Lepisosteus tristœchus_ (Bloch). Cuba.
]

The great alligator-gar, _Lepisosteus tristœchus_, reaches a length of
twenty feet or more, and is a notable inhabitant of the streams about
the Gulf of Mexico. Its snout is broad and relatively wide, and its
teeth are very strong. It is very destructive to all sorts of
food-fishes. Its flesh is worthless, and its enameled scales resist a
spear or sometimes even shot. It breathes air to a certain extent by its
lungs, but soon dies in foul water, not having the tenacity of life seen
in _Amia_.

=Embryology of the Garpike.=—Mr. Alexander Agassiz has given an account
of the embryology of the garpike, of which the following is an abstract:

"The garpike comes up the St. Lawrence in May, lays its eggs about the
20th, and then disappears. The eggs are large, viscous, stick fast in an
isolated way to whatever they fall upon, and look much like those of
toads, having a large outer membrane and a small yolk. Artificial
fecundation failed, but about 500 naturally-laid eggs were secured, of
which all but 30 perished through mold. The young began to hatch in six
days. Out of 30 young hatched, 27 lived until the 15th of July.
Connection with the sharks appears in the similarity of the branchial
arches and by the presence of the lateral fold in which the pectoral
fins are formed; the way the tail is developed is very like that of the
bony fishes. Among the Ganoids it appears, as well as in ordinary
fishes, the dorsal cord is straight at first, then assumes a slightly
upward curve at the extremity, when finally there appears the beginning
of a lobe underneath, pointing to a complete heterocercal tail. All this
is as in the bony fishes, but this is the permanent condition of the
garpike, while in the bony fishes the extremity of the dorsal cord
becomes extinct. The mode of development of the pectoral lobe (very
large in this species) furnishes another resemblance. In the brain, and
in the mode of formation of the gills, a likeness to the sharks is
noticeable. The young garpikes move very slowly, and seem to float
quietly, save an exceedingly rapid vibration of the pectorals and the
tip of the tail. They do not swim about much, but attach themselves to
fixed objects by an extraordinary horseshoe-shaped ring of
sucker-appendages about the mouth. These appendages remain even after
the snout has become so extended that the ultimate shape is hinted at;
and furthermore, it is a remnant of this feature that forms the fleshy
bulb at the end of the snout in the adult. The investigations thus far
show that the young garpike has many characteristics in common with the
sharks and skates, but it is not so different from the bony fishes as
has been supposed."

=Fossil Garpikes.=—A number of fossil garpikes, referred by Cope to the
genus _Clastes_ and by Eastman and Woodward to _Lepidosteus_, are found
in the Eocene of Europe and America. The most perfect of these remains
is called _Lepisosteus atrox_, upward of four feet long, as large as an
alligator-gar, which the species much resembles. Although found in the
Eocene, Dr. C. R. Eastman declares that "it has no positively archaic
features. If we inquire into the more remote or pre-Eocene history of
Lepidosteids, palæontology gives no answer. They blossom forth suddenly
and fully differentiated at the dawn of the Tertiary, without the least
clue to their ancestry, unheralded and unaccompanied by any intermediate
forms, and they have remained essentially unchanged ever since."

Another fossil species is _Lepisosteus fimbriatus_, from the Upper
Eocene of England. Scales and other fragments of garpikes are found in
Germany, Belgium, and France, in Eocene and Miocene rocks. On some of
these the nominal genera _Naisia_, _Trichiurides_, and _Pneumatosteus_
are founded. _Clastes_, regarded by Eastman as fully identical with
_Lepisosteus_, is said to have the "mandibular ramus without or with a
reduced fissure of the dental foramen, and without the groove continuous
with it in _Lepisosteus_. One series of large teeth, with small ones
external to them on the dentary bone." Most of the fossil forms belong
to _Clastes_, but the genus shows no difference of importance which will
distinguish it from the ordinary garpike.

[Illustration:

  FIG. 24.—Lower jaw of _Amia calva_ Linnæus, showing the gular plate.
]

=Order Halecomorphi.=—To this order belong the allies, living or
extinct, of the bowfin (_Amia_), having for the most part cycloid scales
and vertebræ approaching those of ordinary fishes. The resemblance to
the _Isospondyli_, or herring group, is indicated in the name (Halec, a
herring; μορφή, form). The notochord is persistent, the vertebræ
variously ossified. The opercles are always complete. The
branchiostegals are broad and there is always a gular plate. The teeth
are pointed, usually strong. There is no infraclavicle. Fulcra are
present or absent. The supports of the dorsal and anal are equal in
number to the rays. Tail heterocercal. Scales thin, mostly cycloid, but
bony at base, not jointed with each other. Mandible complex, with
well-developed splenial rising into a coronoid process, which is
completed by a distinct coronoid bone. Pectoral fin with more than five
actinosts; scales ganoid or cycloid. In the living forms the air-bladder
is connected with the œsophagus through life; optic chiasma present;
intestine with a spiral valve. This group corresponds to the _Amioidei_
of Lütken and essentially to the _Cycloganoidei_ of Gill. The
_Protospondyli_ (προτός, before; σπόνδυλος, vertebra) of Woodward
contains essentially the same elements.

=Pachycormidæ.=—In the family of _Pachycormidæ_ the notochord is
persistent, the ethmoids and vomer fused and projecting between the
maxillaries to form the prominent snout, the teeth large, the body
fusiform, the dorsal short, with slender rays and few fulcra or none,
and the scales are thin and rhombic. The numerous species are
characteristic of the Triassic, Jurassic, and Cretaceous. In _Sauropsis_
(_longimana_) the body is elongate, and the pectoral fins are large and
sickle-shaped. _Euthynotus_ has small fulcra. In _Pachycormus_
(_macropterus_, _esocinus_, etc.) the form is robust and the ventral
fins are wanting. In _Hypsycormus_ ventrals are present, and the caudal
deeply forked.

In the American family of _Protosphyrænidæ_ the jaws are armed with very
strong teeth, as in the Barracuda, which, however, the species do not
resemble in other respects. _Protosphyræna nitida_, _perniciosa_, and
numerous other extinct forms, some of them of large size, were voracious
inhabitants of the Cretaceous seas, and are found fossil, especially in
North Carolina and Kansas. Numerous species called _Erisichthe_ and
_Pelecopterus_ are all referred by Hay to _Protosphyræna_. In this
family the scapula and coracoids are ossified, and perhaps the vertebræ
also, and, as Dr. Hay has recently suggested, the _Protosphyrænidæ_ may
really belong to the _Isospondyli_. In any event, they stand on the
border-line between the most fish-like of the Ganoids and the most
archaic of the bony fishes.

The _Liodesmidæ_ (genus _Liodesmus_) are much like _Amia_, but the
notochord is persistent, its sheath without ossification. _Liodesmus
gracilis_ and _L. sprattiformis_ occur in the lithographic stones of
Bavaria. Woodward places _Liodesmus_ with _Megalurus_ among the
_Amiidæ_.

=The Bowfins: Amiidæ.=—The _Amiidæ_ have the vertebræ more complete. The
dorsal fin is many-rayed and is without distinct fulcra. The
diamond-shaped enameled scales disappear, giving place to cycloid
scales, which gradually become thin and membranous in structure. A
median gular plate is developed between the branchiostegals. The tail is
moderately heterocercal, and the head covered with a bony coat of mail.

The family of _Amiidæ_ contains a single recent species, _Amia calva_,
the only living member of the order _Halecomorphi_. The bowfin, or
grindle, is a remarkable fish abounding in the lakes and swamps of the
Mississippi Valley, the Great Lake region, and southward to Virginia,
where it is known by the imposing but unexplained title of John A.
Grindle. In the Great Lakes it is usually called "dogfish," because even
the dogs will not eat it, and "lawyer," because, according to Dr.
Kirtland, "it will bite at anything and is good for nothing when
caught."

The bowfin reaches a length of two and one half feet, the male being
smaller than the female and marked by an ocellated black spot on the
tail. Both sexes are dark mottled green in color. The flesh of the
species is very watery, pasty, much of the substance evaporating when
exposed to the air. It is ill-flavored, and is not often used as food.
The species is very voracious and extremely tenacious of life. Its
well-developed lung enables it to breathe even when out of the water,
and it will live in the air longer than any other fish of American
waters, longer even than the horned pout (_Ameiurus_) or the mud-minnow
(_Umbra_). As a game fish the grindle is one of the very best, if the
angler does not care for the flesh of what he catches, it being one of
the hardest fighters that ever took the hook.

[Illustration:

  FIG. 25.—Bowfin (female), _Amia calva_ Linnæus. Lake Michigan.
]

The _Amiidæ_ retain many of the Ganoid characters, though approaching
more nearly than any other of the Ganoids to the modern herring tribe.
For this reason the name _Halecomorphi_ (shad-formed) was given to this
order by Professor Cope. The gular plate found in Amia and other Ganoids
reappears in the herring-like family of _Elopidæ_, which includes the
tarpon and the ten-pounder.

Woodward unites the extinct genera called _Cyclurus_, _Notæus_,
_Amiopsis_, _Protamia_, _Hypamia_, and _Pappichthys_ with _Amia_.
_Pappichthys_ (_corsoni_, etc.), from the Wyoming Eocene, is doubtless a
valid genus, having but one row of teeth in each jaw, and _Amiopsis_ is
also recognized by Hay. Woodward refers to _Amia_ the following extinct
species: _Amia valenciennesi_, from the Miocene of France; _Amia
macrocephala_, from the Miocene of Bohemia; and _Amia ignota_, from the
Eocene of Paris. Other species of Amia are known from fragments. Several
of these are from the Eocene of Wyoming and Colorado. Some of them have
a much shorter dorsal fin than that of _Amia calva_ and may be
generically different.

[Illustration:

  FIG. 26.—_Megalurus elegantissimus_ Wagner. Family _Amiidæ_. (After
    Zittel.)
]

The genus _Megalurus_ differs from _Amia_ in the still shorter dorsal
fin, less than one-third the length of the back. The body is elongate
and much depressed. _Megalurus lepidotus_ and several other species are
found in the lithographic stones of Bavaria and elsewhere.

=The Oligopleuridæ.=—In the extinct family _Oligopleuridæ_ the scales
are cycloid, the bones of the head scarcely enameled, and the vertebræ
well ossified. Fulcra are present, and the mouth is large, with small
teeth. The genera are _Oligopleurus_, _Ionoscopus_, and _Spathiurus_,
the species not very numerous and chiefly of the Cretaceous. _Ionoscopus
cyprinoides_ of the lithographic shales of Bavaria is a characteristic
species.

From the three families last named, with the _Pholidophoridæ_, there is
an almost perfect transition from the Ganoid fishes to teleosteans of
the order of _Isospondyli_, the primitive order from which all other
bony fishes are perhaps descended. The family of _Leptolepidæ_,
differing from _Oligopleuridæ_ in the absence of fulcra, is here placed
with the _Isospondyli_, but it might about as well be regarded as
Ganoid.



                              CHAPTER III
                              ISOSPONDYLI


=THE Subclass Teleostei, or Bony Fishes.=—The fishes which still remain
for discussion constitute the great subclass or series of _Teleostei_
(τελεός, true; οστέον, bone), or bony fishes. They lack wholly or partly
the Ganoid traits, or show them only in the embryo. The tail is
slightly, if at all, heterocercal; the actinosts of the pectoral fins
are few and large, rarely over five in number, except among the eels;
the fulcra disappear; the air-bladder is no longer cellular, except in
very rare cases, nor does it assist in respiration. The optic nerves are
separate, one running to each eye without crossing; the skeleton is
almost entirely bony, the notochord usually disappearing entirely with
age; the valves in the arterial bulb are reduced in number, and the
spiral valve of the intestines disappears. Traces of each of the Ganoid
traits may persist somewhere in some group, but as a whole we see a
distinct specialization and a distinct movement toward the fish type,
with the loss of characters distinctive of sharks, Dipnoans, and
Ganoids. In a general way the skeleton of all Teleosts corresponds with
that of the striped bass (see Figs. 22, 23, Vol. I), and the visceral
anatomy is in all cases sufficiently like that of the sunfish (Fig. 16,
Vol. I).

The mesocoracoid or precoracoid arch, found in all Ganoids, persists in
the less specialized types of bony fishes, although no trace of it is
found in the perch-like forms. With all this, there is developed among
the bony fishes an infinite variety in details of structure. For this
reason the _Teleostei_ must be broken into many orders, and these orders
are very different in value and in degrees of distinctness, the various
groups being joined by numerous and puzzling intergradations.

=Order Isospondyli.=—Of the various subordinate groups of bony fishes,
there can be no question as to which is most primitive in structure, or
as to which stands nearest the orders of Ganoids. Earliest of the bony
fishes in geological time is the order of _Isospondyli_ (ἴσος, equal;
σπόνδυλος, vertebra), containing the allies, recent or fossil, of the
herring and the trout. This order contains those soft-rayed fishes in
which the ventral fins are abdominal, a mesocoracoid or precoracoid arch
is developed, and the anterior vertebræ are unmodified and essentially
similar to the others. The orbitosphenoid is present in all typical
forms. In certain forms of doubtful affinity (_Iniomi_) the mesocoracoid
is wanting or lost in degeneration. Through the _Isospondyli_ all the
families of fishes yet to be considered are apparently descended, their
ancestors being Ganoid fishes and, still farther back, the
Crossopterygians.

Woodward gives this definition of the _Isospondyli_: "Notochord varying
in persistence, the vertebral centra usually complete, but none
coalesced; tail homocercal, but hæmal supports not much expanded or
fused. Symplectic bone present, mandible simple, each dentary consisting
only of two elements (dentary and articulo-angular), with rare rudiments
of a splenoid on the inner side. Pectoral arch suspended from the
cranium; precoracoid (mesocoracoid) arch present; infraclavicular plates
wanting. Pelvic (ventral) fins abdominal. Scales ganoid only in the less
specialized families. In the living forms air-bladder connected with the
œsophagus in the adult; optic nerves decussating (without chiasma), and
intestine either wanting spiral valve or with an incomplete
representative of it."

=The Classification of the Bony Fishes.=—The classification of fishes
has been greatly complicated by the variety of names applied to groups
which are substantially but not quite identical one with another. The
difference in these schemes of classification lies in the point of view.
In all cases a single character must be brought to the front; such
characters never stand quite alone, and to lay emphasis on another
character is to make an alteration large or small in the name or in the
boundaries of a class or order. Thus the _Ostariophysi_ with the
_Isospondyli_, _Haplomi_, and a few minor groups make up the great
division of the _Abdominales_. These are fishes in which the ventral
fins are abdominal, that is, inserted backward, so that the pelvis is
free from the clavicle, the two sets of limbs being attached to
different parts of the skeleton. Most of the abdominal fishes are also
soft-rayed fishes, that is, without consecutive spines in the dorsal and
anal fins, and they show a number of other archaic peculiarities. The
Malacopterygians (μαλακός, soft; πτερύξ, fin) of Cuvier therefore
correspond very nearly to the _Abdominales_. But they are not quite the
same, as the spiny-rayed barracudas and mullets have abdominal ventrals,
and many unquestioned thoracic or jugular fishes, as the sea-snails and
brotulids, have lost, through degeneration, all of their fin-spines.

In nearly but not quite all of the Abdominal fishes the slender tube
connecting the air-bladder with the œsophagus persists through life.
This character defines Müller's order of _Physostomi_ (φυσός, bladder;
στόμα, mouth), as opposed to his _Physoclysti_ (φυσός, bladder;
κλεῖστός, closed), in which this tube is present in the embryo or larva
only. Thus the _Thoracices_ and _Jugulares_, or fishes having the
ventrals thoracic or jugular, together correspond almost exactly to the
Acanthopterygians, (ακανθα, spine; πτερύξ, fin), or spiny-rayed fishes
of Cuvier, or to the _Physoclysti_ of Müller. The Malacopterygians, the
_Abdominales_, and the _Physostomi_ are in the same way practically
identical groups. As the spiny-rayed fishes have mostly ctenoid scales,
and the soft-rayed fishes cycloid scales, the _Physostomi_ correspond
roughly to Agassiz's _Cycloidei_, and the _Physoclysti_ to his
_Ctenoidei_.

But in none of these cases is the correspondence perfectly exact, and in
any system of classification we must choose characters for primary
divisions so ancient and therefore so permanent as to leave no room for
exceptions. The extraordinary difficulty of doing this, with the
presence of most puzzling intergradations, has led Dr. Gill to suggest
that the great body of bony fishes, soft-rayed and spiny-rayed,
abdominal, thoracic, and jugular alike, be placed in a single great
order which he calls _Teleocephali_ (τελεός, perfect; κεφαλή, head). The
aberrant forms with defective skull and membrane-bones he would separate
as minor offshoots from this great mass with the name of separate
orders. But while the divisions of _Teleocephali_ are not strongly
differentiated, their distinctive characters are real, ancient, and
important, while those of the aberrant groups, called orders by Gill (as
_Plectognathi_, _Pediculati_, _Hemibranchii_), are relatively modern and
superficial, which is one reason why they are more easily defined. There
seems to us no special advantage in the retention of a central order
_Teleocephali_, from which the divergent branches are separated as
distinct orders.

While our knowledge of the osteology and embryology of most of the
families of fishes is very incomplete, it is evident that the
relationships of the groups cannot be shown in any linear series or by
any conceivable arrangement of orders and suborders. The living teleost
fishes have sprung from many lines of descent, their relationships are
extremely diverse, and their differences are of every possible degree of
value. The ordinary schemes have magnified the value of a few common
characters, at the same time neglecting other differences of equal
value. No system of arrangement which throws these fishes into large
groups can ever be definite or permanent.

=Relationships of Isospondyli.=—For our purposes we may divide the
physostomous fishes as understood by Müller into several orders, the
most primitive, the most generalized, and economically the most
important being the order of _Isospondyli_. This order contains those
bony fishes which have the anterior vertebræ unaltered (as distinguished
from the _Ostariophysi_), the skull relatively complete, or at least not
eel-like, the mesocoracoid typically developed, but atrophied in
deep-sea forms and finally lost, the orbitosphenoid present. In all the
species the ventral fins are abdominal and normally composed of more
than six rays; the air-duct is developed. The scales are chiefly cycloid
and the fins are without true spines. In many ways the order is more
primitive than _Nematognathi_, _Plectospondyli_, or _Apodes_. It is
certain that it began earlier in geological time than any of these. On
the other hand, the _Isospondyli_ are closely connected through the
_Berycoidei_ with the highly specialized fishes. The continuity of the
natural series is therefore interrupted by the interposition of the side
branches of Ostariophysans and eels before considering the _Haplomi_ and
the other transitional forms. The forms called _Iniomi_, which lack the
mesocoracoid and the orbitosphenoid, have been lately transferred to the
_Haplomi_ by Boulenger. This arrangement is probably a step in advance.

Ganoid traits are present in certain families of _Isospondyli_. Among
these are the gular plate (found in _Amia_ and the _Elopidæ_), doubtless
derived from the similar structure in earlier Ganoids; additional valves
in the arterial bulb in the cellular air-bladder of _Notopterus_ and
_Osteoglossum_, the spiral intestinal valve in _Chirocentridæ_, and the
ganoid scales of the extinct _Leptolepidæ_.

=The Clupeoidea.=—The _Isospondyli_ are divisible into numerous
families, which may be grouped roughly under three subdivisions,
_Clupeoidea_, the herring-like forms; the _Salmonoidea_, the trout-like
forms; and the _Iniomi_, or lantern-fishes, and their allies. The
last-named group should probably be removed from the order of
_Isospondyli_. In the _Clupeoidea_, the allies of the great family of
the herring, the shoulder-girdle is normally developed, retaining the
mesocoracoid arch on its inner edge, and through the post-temporal is
articulated above with the cranium. The fishes in this group lack the
adipose fin which is characteristic of most of the higher or salmon-like
families.

[Illustration:

  FIG. 27.—_Leptolepis dubius_ Blainville, Lithographic Stone. (After
    Woodward.)
]

=The Leptolepidæ.=—Most primitive of the _Isospondyli_ is the extinct
family of _Leptolepidæ_, closely allied to the Ganoid families of
_Pholidophoridæ_ and _Oligopleuridæ_. It is composed of graceful,
herring-like fishes, with the bones of the head thin but covered with
enamel, and the scales thin but firm and enameled on their free portion.
There are no fulcra and there is no lateral line. The vertebræ are well
developed, but always pierced by the notochord. The genera are
_Lycoptera_, _Leptolepis_, _Æthalion_, and _Thrissops_. In _Lycoptera_
of the Jurassic of China the vertebral centra are feebly developed, and
the dorsal fin short and posterior. In _Leptolepis_ the anal is short
and placed behind the dorsal. There are many species, mostly from the
Triassic and lithographic shales of Europe, one being found in the
Cretaceous. _Leptolepis coryphænoides_ and _Leptolepis dubius_ are among
the more common species. _Æthalion_ (_knorri_) differs in the form of
the jaws. In _Thrissops_ the anal fin is long and opposite the dorsal.
_Thrissops salmonea_ is found in the lithographic stone; _Thrissops
exigua_ in the Cretaceous. In all these early forms there is a hard
casque over the brain-cavity, as in the living types, _Amia_ and
_Osteoglossum_.

[Illustration:

  FIG. 28.—Ten-pounder, _Elops saurus_ L. An ally of the earliest bony
    fishes. Virginia.
]

[Illustration:

  FIG. 29.—A primitive Herring-like fish, _Holcolepis lewesiensis_,
    Mantell, restored. Family _Elopidæ_. English Chalk. (After
    Woodward.)
]

=The Elopidæ.=—The family of _Elopidæ_ contains large fishes
herring-like in form and structure, but having a flat membrane-bone or
gular plate between the branches of the lower jaw, as in the Ganoid
genus _Amia_. The living species are few, abounding in the tropical
seas, important for their size and numbers, though not valued as
food-fishes save to those who, like the Hawaiians and Japanese, eat
fishes raw. These people prefer for that purpose the white-meated or
soft-fleshed forms like _Elops_ or _Scarus_ to those which yield a
better flavor when cooked.

The ten-pounder (_Elops saurus_), pike-like in form but with very weak
teeth, is found in tropical America. _Elops machnata_, the jack
mariddle, the awaawa of the Hawaiians, abounding in the Pacific, is
scarcely if at all different.

[Illustration:

  FIG. 30.—Tarpon or Grande Écaille, _Tarpon atlanticus_ Cuv. & Val.
    Florida.
]

The tarpon, called also grande écaille, silver-king, and sable (_Tarpon
atlanticus_), is a favorite game-fish along the coasts of Florida and
Carolina. It takes the hook with great spirit, and as it reaches a
length of six feet or more it affords much excitement to the successful
angler. The very large scales are much used in ornamental work.

A similar species of smaller size, also with the last ray of the dorsal
very much produced, is _Megalops cyprinoides_ of the East Indies. Other
species occur in the South Seas.

Numerous fossil genera related to _Elops_ are found in the Cretaceous
and Tertiary rocks. _Holcolepis lewesiensis_ (wrongly called
_Osmeroides_) is the best-known European species. Numerous species are
referred to _Elopopsis_. _Megalops prisca_ and species of _Elops_ also
occur in the London Eocene.

In all these the large parietals meet along the median line of the
skull. In the closely related family of _Spaniodontidæ_ the parietals
are small and do not meet. All the species of this group, united by
Woodward with the _Elopidæ_, are extinct. These fishes preceded the
_Elopidæ_ in the Cretaceous period. Leading genera are _Thrissopater_
and _Spaniodon_, the latter armed with large teeth. _Spaniodon blondeli_
is from the Cretaceous of Mount Lebanon. Many other species are found in
the European and American Cretaceous rocks, but are known from imperfect
specimens only.

_Sardinius_, an American Cretaceous fossil herring, may stand near
_Spaniodon_. _Rhacolepis buccalis_ and _Notelops brama_ are found in
Brazil, beautifully preserved in concretions of calcareous mud supposed
to be of Cretaceous age.

The extinct family of _Pachyrhizodontidæ_ is perhaps allied to the
_Elopidæ_. Numerous species of _Pachyrhizodus_ are found in the
Cretaceous of southern England and of Kansas.

=The Albulidæ.=—The _Albulidæ_, or lady-fishes, characterized by the
blunt and rounded teeth, are found in most warm seas. _Albula vulpes_ is
a brilliantly silvery fish, little valued as food. The metamorphosis
(see Fig. 112, Vol. I) which the larva undergoes is very remarkable. It
is probably, however, more or less typical of the changes which take
place with soft-rayed fishes generally, though more strongly marked in
_Albula_ and in certain eels than in most related forms. Fossils allied
to _Albula_, _Albula oweni_, _Chanoides macropomus_, are found in the
Eocene of Europe; _Syntegmodus altus_ in the Cretaceous of Kansas. In
_Chanoides_, the most primitive genus, the teeth are much fewer than in
_Albula_. _Plethodus_ and _Thryptodus_, with peculiar dental plates on
the roof and floor of the mouth, probably constitute a distinct family,
_Thryptodontidæ_. The species are found in European and American rocks,
but are known from imperfect specimens only.

[Illustration:

  FIG. 31.—The Lady-fish, _Albula vulpes_ (Linnæus). Florida.
]

=The Chanidæ.=—The _Chanidæ_, or milkfishes, constitute another small
archaic type, found in the tropical Pacific. They are large, brilliantly
silvery, toothless fishes, looking like enormous dace, swift in the
water, and very abundant in the Gulf of California, Polynesia, and
India. The single living species is the _Awa_, or milkfish, _Chanos
chanos_, largely used as food in Hawaii. Species of _Prochanos_ and
_Chanos_ occur in the Cretaceous, Eocene, and Miocene. Allied to
_Chanos_ is the Cretaceous genus _Ancylostylos_ (_gibbus_), probably the
type of a distinct family, toothless and with many-rayed dorsal.

[Illustration:

  FIG. 32.—Milkfish, _Chanos chanos_ (L.). Mazatlan.
]

[Illustration:

  FIG. 33.—Mooneye, _Hiodon tergisus_ Le Sueur. Ecorse, Mich.
]

=The Hiodontidæ.=—The _Hiodontidæ_, or mooneyes, inhabit the rivers of
the central portion of the United States and Canada. They are shad-like
fishes with brilliantly silvery scales and very strong sharp teeth,
those on the tongue especially long. They are very handsome fishes and
take the hook with spirit, but the flesh is rather tasteless and full of
small bones, much like that of the milkfish. The commonest species is
_Hiodon tergisus_. No fossil _Hiodontidæ_ are known.

[Illustration:

  FIG. 34.—_Istieus grandis_ Agassiz. Family _Pterothrissidæ_. (After
    Zittel.)
]

[Illustration:

  FIG. 35.—_Chirothrix libanicus_ Pictet & Humbert. Cretaceous of Mt.
    Lebanon. (After Woodward.)
]

=The Pterothrissidæ.=—The _Pterothrissidæ_ are sea-fishes like _Albula_,
but more slender and with a long dorsal fin. They live in deep or cold
waters along the coasts of Japan, where they are known as gisu. The
single species is _Pterothrissus gissu_. The fossil genus _Istieus_,
from the Upper Cretaceous, probably belongs near the _Pterothrissidæ_.
_Istieus grandis_ is the best-known species. Another ancient family, now
represented by a single species, is that of the _Chirocentridæ_, of
which the living type is _Chirocentrus dorab_, a long, slender, much
compressed herring-like fish, with a saw-edge on the belly, found in the
East Indies, in which region _Chirocentrus polyodon_ occurs as a fossil.
Numerous fossil genera related to _Chirocentrus_ are enumerated by
Woodward, most of them to be referred to the related family of
_Ichthyodectidæ_ (_Saurodontidæ_). Of these, _Portheus_,
_Ichthyodectes_, _Saurocephalus_ (_Saurodon_), and _Gillicus_ are
represented by numerous species, some of them fishes of immense size and
great voracity. _Portheus molossus_, found in the Cretaceous of
Nebraska, is remarkable for its very strong teeth. Species of other
genera are represented by numerous species in the Cretaceous of both the
Rocky Mountain region and of Europe.

[Illustration:

  FIG. 36.—Gigantic skeleton of _Portheus molossus_ Cope. (Photograph by
    Charles H. Sternberg.)
]

=The Ctenothrissidæ.=—A related family, _Ctenothrissidæ_, is represented
solely by extinct Cretaceous species. In this group the body is robust
with large scales, ctenoid in _Ctenothrissa_, cycloid in _Aulolepis_.
The fins are large, the belly not serrated, and the teeth feeble.
_Ctenothrissa vexillifera_ is from Mount Lebanon. Other species occur in
the European chalk. In the small family of _Phractolæmidæ_ the
interopercle, according to Boulenger, is enormously developed.

[Illustration:

  FIG. 37.—_Ctenothrissa vexillifera_ Pictet, restored. Mt. Lebanon
    Cretaceous. (After Woodward.)
]

=The Notopteridæ.=—The _Notopteridæ_ is another small family in the
rivers of Africa and the East Indies. The body ends in a long and
tapering fin, and, as usual in fishes which swim by body undulations,
the ventral fins are lost. The belly is doubly serrate. The air-bladder
is highly complex in structure, being divided into several compartments
and terminating in two horns anteriorly and posteriorly, the anterior
horns being in direct communication with the auditory organ. A fossil
_Notopterus_, _N. primævus_, is found in the same region.

=The Clupeidæ.=—The great herring family, or _Clupeidæ_, comprises
fishes with oblong or herring-shaped body, cycloid scales, and feeble
dentition. From related families it is separated by the absence of
lateral line and the division of the maxillary into three pieces. In
most of the genera the belly ends in a serrated edge, though in the true
herring this is not very evident, and in some the belly has a blunt
edge. Some of the species live in rivers, some ascend from the sea for
the purpose of spawning. The majority are confined to the ocean. Among
all the genera, the one most abundant in individuals is that of
_Clupea_, the herring. Throughout the North Atlantic are immense schools
of _Clupea harengus_. In the North Pacific on both shores another
herring, _Clupea pallasi_, is equally abundant, and with the same market
it would be equally valuable. As salted, dried, or smoked fish the
herring is found throughout the civilized world, and its spawning and
feeding-grounds have determined the location of cities.

[Illustration:

  FIG. 38.—Herring, _Clupea harengus_ L. New York.
]

The genus _Clupea_, of northern distribution, has the vertebræ in
increased number (56), and there are weak teeth on the vomer. Several
other genera are very closely related, but ranging farther south they
have, with other characters, fewer (46 to 50) vertebræ. The alewife, or
branch-herring (_Pomolobus pseudoharengus_), ascends the rivers to spawn
and has become landlocked in the lakes of New York. The skipjack of the
Gulf of Mexico, _Pomolobus chrysochloris_, becomes very fat in the sea.
The species becomes landlocked in the Ohio River, where it thrives as to
numbers, but remains lean and almost useless as food. The glut-herring,
_Pomolobus æstivalis_, and the sprat, _Pomolobus sprattus_, of Europe
are related forms.

[Illustration:

  FIG. 39.—Alewife, _Pomolobus pseudoharengus_ (Wilson). Potomac River.
]

Very near also to the herring is the shad (_Alosa sapidissima_) of the
eastern coasts of America, and its inferior relatives, the shad of the
Gulf of Mexico (_Alosa alabamæ_), the Ohio River shad (_Alosa
ohiensis_), very lately discovered, the Allice shad (_Alosa alosa_) of
Europe, and the Thwaite shad (_Alosa finta_). In the genus _Alosa_ the
cheek region is very deep, giving the head a form different from that
seen in the herring.

The American shad is the best food-fish in the family, peculiarly
delicate in flavor when broiled, but, to a greater degree than occurs in
any other good food-fish, its flesh is crowded with small bones. The
shad has been successfully introduced into the waters of California,
where it abounds from Puget Sound to Point Concepcion, ascending the
rivers to spawn in May as in its native region, the Atlantic coast.

The genus _Sardinella_ includes species of rich flesh and feeble
skeleton, excellent when broiled, when they may be eaten bones and all.
This condition favors their preservation in oil as "sardines." All the
species are alike excellent for this purpose. The sardine of Europe is
the _Sardinella pilchardus_, known in England as the pilchard. The
"Sardina de España" of Cuba is _Sardinella pseudohispanica_, the sardine
of California, _Sardinella cærulea_. _Sardinella sagax_ abounds in
Chile, and _Sardinella melanosticta_ is the valued sardine of Japan.

In the tropical Pacific occur other valued species, largely belonging to
the genus _Kowala_. The genus _Harengula_ contains small species with
very large, firm scales which do not fall when touched, as is generally
the case with the sardines. Most common of these is _Harengula sardina_
of the West Indies. Similar species occur in southern Europe and in
Japan.

[Illustration:

  FIG. 40.—Menhaden, _Brevoortia tyrannus_ (Latrobe). Wood's Hole, Mass.
]

In _Opisthonema_, the thread-herring, the last dorsal ray is much
produced, as in the gizzard-shad and the tarpon. The two species known
are abundant, but of little commercial importance. Of greater value are
the menhaden, or the moss-bunker, _Brevoortia tyrannus_, inhabiting the
sandy coasts from New England southward. It is a coarse and bony fish,
rarely eaten when adult, although the young in oil makes acceptable
sardines. It is used chiefly for oil, the annual yield exceeding in
value that of whale-oil. The refuse is used as manure, a purpose for
which the fishes are often taken without preparation, being carried
directly to the cornfields. From its abundance this species of inferior
flesh exceeds in commercial value almost all other American fishes
excepting the cod, the herring, and the quinnat salmon.

One of the most complete of fish biographies is that of Dr. G. Brown
Goode on the "Natural and Economic History of Menhaden."

Numerous other herring-like forms, usually with compressed bodies, dry
and bony flesh, and serrated bellies, abound in the tropics and are
largely salted and dried by the Chinese. Among these are _Ilisha
elongata_ of the Chinese coast. Related forms occur in Mexico and
Brazil.

The round herrings, small herrings which have no serrations on the
belly, are referred by Dr. Gill to the family of _Dussumieriidæ_. These
are mostly small tropical fishes used as food or bait. One of these, the
Kobini-Iwashi of Japan (_Stolephorus japonicus_), with a very bright
silver band on the side, has considerable commercial importance. Very
small herrings of this type in the West Indies constitute the genus
_Jenkinsia_, named for Dr. Oliver P. Jenkins, the first to study
seriously the fishes of Hawaii. Other species constitute the widely
distributed genera _Etrumeus_ and _Dussumieria_. _Etrumeus sardina_ is
the round herring of the Virginia coast. _Etrumeus micropus_ is the
Etrumei-Iwashi of Japan and Hawaii.

[Illustration:

  FIG. 41.—A fossil Herring, _Diplomystus humilis_ Leidy. (From a
    specimen obtained at Green River, Wyo.) The scutes along the back
    lost in the specimen. Family _Clupeidæ_.
]

Fossil herring are plentiful and exist in considerable variety, even
among the _Clupeidæ_ as at present restricted. _Histiothrissa_ of the
Cretaceous seems to be allied to _Dussumieria_ and _Stolephorus_.
Another genus, from the Cretaceous of Palestine, _Pseudoberyx_
(_syriacus_, etc.), having pectinated scales, should perhaps constitute
a distinct subfamily, but the general structure is like that of the
herring. More evidently herring-like is _Scombroclupea_
(_macrophthalma_). The genus _Diplomystus_, with enlarged scales along
the back, is abundantly represented in the Eocene shales of Green River,
Wyoming. Species of similar appearance, usually but wrongly referred to
the same genus, occur on the coasts of Peru, Chile, and New South Wales.
A specimen of _Diplomystus humilis_ from Green River is here figured.
Numerous herring, referred to _Clupea_, but belonging rather to
_Pomolobus_, or other non-Arctic genera, have been described from the
Eocene and later rocks.

Several American fossil herring-like fishes, of the genus _Leptosomus_,
as _Leptosomus percrassus_, are found in the Cretaceous of South Dakota.

Fossil species doubtfully referred to _Dorosoma_, but perhaps allied
rather to the thread-herring (_Opisthonema_), being herrings with a
prolonged dorsal ray, are recorded from the early Tertiary of Europe.
Among these is _Opisthonema doljeanum_ from Austria.

[Illustration:

  FIG. 42.—Hickory-shad, _Dorosoma cepedianum_ (Le Sueur). Potomac
    River.
]

=The Dorosomatidæ.=—The gizzard-shad, _Dorosomatidæ_, are closely
related to the _Clupeidæ_, differing in the small contracted toothless
mouth and reduced maxillary. The species are deep-bodied, shad-like
fishes of the rivers and estuaries of eastern America and eastern Asia.
They feed on mud, and the stomach is thickened and muscular like that of
a fowl. As the stomach has the size and form of a hickory-nut, the
common American species is often called hickory-shad. The gizzard-shad
are all very poor food-fish, bony and little valued, the flesh full of
small bones. The belly is always serrated. In three of the four genera
of _Dorosomatidæ_ the last dorsal ray is much produced and whip-like.
The long and slender gill-rakers serve as strainers for the mud in which
these fishes find their vegetable and animal food. _Dorosoma
cepedianum_, the common hickory-shad or gizzard-shad, is found in
brackish river-mouths and ponds from Long Island to Texas, and
throughout the Mississippi Valley in all the large rivers. Through the
canals it has entered Lake Michigan. The Konoshiro, _Clupanodon
thrissa_, is equally common in China and Japan.

=The Engraulididæ.=—The anchovies (_Engraulididæ_) are dwarf herrings
with the snout projecting beyond the very wide mouth. They are small in
size and weak in muscle, found in all warm seas, and making a large part
of the food of the larger fish. The genus _Engraulis_ includes the
anchovy of Europe, _Engraulis encrasicholus_, with similar species in
California, Chile, Japan, and Australia. In this genus the vertebræ are
numerous, the bones feeble, and the flesh tender and oily. The species
of _Engraulis_ are preserved in oil, often with spices, or are made into
fish-paste, which is valued as a relish. The genus _Anchovia_ replaces
_Engraulis_ in the tropics. The vertebræ are fewer, the bones firm and
stiff, and the flesh generally dry. Except as food for larger fish,
these have little value, although existing in immense schools. Most of
the species have a bright silvery band along the side. The most familiar
of the very numerous species is the silver anchovy, _Anchovia browni_,
which abounds in sandy bays from Cape Cod to Brazil. Several other
genera occur farther southward, as well as in Asia, but _Engraulis_ only
is found in Europe. Fossil anchovies called _Engraulis_ are recorded
from the Tertiary of Europe.

[Illustration:

  FIG. 43.—A Silver Anchovy, _Anchovia perthecata_ (Goode & Bean).
    Tampa.
]

[Illustration:

  FIG. 44.—_Notogoneus osculus_ Cope. Green River Eocene. Family
    _Gonorhynchidæ_.
]

=Gonorhynchidæ.=—To the _Isospondyli_ belongs the small primitive family
of _Gonorhynchidæ_, elongate fishes with small mouth, feeble teeth, no
air-bladder, small scales of peculiar structure covering the head, weak
dentition, the dorsal fin small, and posterior without spines. The
mesocoracoid is present as in ordinary _Isospondyli_. _Gonorhynchus
abbreviatus_ occurs in Japan, and _Gonorhynchus gonorhynchus_ is found
in Australia and about the Cape of Good Hope. Numerous fossil species
occur. _Charitosomus lineolatus_ and other species are found in the
Cretaceous of Mount Lebanon and elsewhere. Species without teeth from
the Oligocene of Europe and America are referred to the genus
_Notogoneus_. _Notogoneus osculus_ occurs in the Eocene fresh-water
deposits at Green River, Wyoming. It bears a very strong resemblance in
form to an ordinary sucker (_Catostomus_), for which reason it was once
described by the name of _Protocatostomus_. The living _Gonorhynchidæ_
are all strictly marine.

In the small family of _Cromeriidæ_ the head and body are naked.

=The Osteoglossidæ.=—Still less closely related to the herring is the
family of _Osteoglossidæ_, huge pike-like fishes of the tropical rivers,
armed with hard bony scales formed of pieces like mosaic. The largest of
all fresh-water fishes is _Arapaima gigas_ of the Amazon region, which
reaches a length of fifteen feet and a weight of 400 pounds. It has
naturally considerable commercial importance, as have species of
_Osteoglossum_, coarse river-fishes which occur in Brazil, Egypt, and
the East Indies. _Heterotis nilotica_ is a large fish of the Nile. In
some or all of these the air-bladder is cellular or lung-like, like that
of a Ganoid.

Allied to the _Osteoglossidæ_ is _Phareodus_ (_Dapedoglossus_), a group
of large shad-like fossil fishes, with large scales of peculiar mosaic
texture and with a bony casque on the head, found in fresh-water
deposits of the Green River Eocene. In the perfect specimens of
_Phareodus_ (or _Dapedoglossus_) _testis_ the first ray of the pectoral
is much enlarged and serrated on its inner edge, a character which may
separate these fishes as a family from the true _Osteoglossidæ_. It does
not, however, appear in Cope's figures, none of his specimens having the
pectorals perfect. In these fishes the teeth are very strong and sharp,
the scales are very large and thin, looking like the scales of a
parrot-fish, the long dorsal is opposite to the anal and similar to it,
and the caudal is truncate. The end of the vertebral column is turned
upward.

Other species are _Phareodus acutus_, known from the jaws; _P.
encaustus_ is known from a mass of thick scales with reticulate or
mosaic-like surface, much as in _Osteoglossum_, and _P. æquipennis_ from
a small example, perhaps immature. _Phareodus testis_ is frequently
found well preserved in the shales at Fossil Station, to the
northwestward of Green River. Whether all these species possess the
peculiar structure of the scales, and whether all belong to one genus,
is uncertain.

[Illustration:

  FIG. 45.—_Phareodus testis_ (Cope). From a specimen 20 inches long
    collected at Fossil, Wyo., in the Museum of the Univ. of Wyoming.
    (Photograph by Prof. Wilbur C. Knight.)
]

In Eocene shales of England occurs _Brychætus muelleri_, a species
closely related to _Phareodus_, but the scales smaller and without the
characteristic reticulate or mosaic structure seen in _Phareodus
encaustus_.

[Illustration:

  FIG. 46.—Deposits of Green River Shales, bearing _Phareodus_, at
    Fossil, Wyoming. (Photograph by Wilbur C. Knight.)
]

[Illustration:

  FIG. 47.—A day's catch of Fossil fishes, _Phareodus_, _Diplomystus_,
    etc. Green River Eocene Shales, Fossil, Wyoming. (Photograph by
    Prof. Wilbur C. Knight.)
]

=The Pantodontidæ.=—The bony casque of _Osteoglossum_ is found again in
the _Pantodontidæ_, consisting of one species, _Pantodon buchholzi_, a
small fish of the brooks of West Africa. As in the _Osteoglossidæ_ and
in the _Siluridæ_, the subopercle is wanting in _Pantodon_.

[Illustration:

  FIG. 48.—_Alepocephalus agassizii_ Goode & Bean. Gulf Stream.
]

The _Alepocephalidæ_ are deep-sea herring-like fishes very soft in
texture and black in color, taken in the oceanic abysses. Some species
may be found in almost all seas below the depth of half a mile.
_Alepocephalus rostratus_ of the Mediterranean has been long known, but
most of the other genera, _Talismania_, _Mitchillina_, _Conocara_, etc.,
are of very recent discovery, having been brought to the surface by the
deep-sea dredging of the _Challenger_, the _Albatross_, the _Blake_, the
_Travailleur_, the _Talisman_, the _Investigator_, the _Hirondelle_, and
the _Violante_.



                               CHAPTER IV
                               SALMONIDÆ


=THE Salmon Family.=—The series or suborder _Salmonoidea_, or allies of
the salmon and trout, are characterized as a whole by the presence of
the adipose fin, a structure also retained in Characins and catfishes,
which have no evident affinity with the trout, and in the
lantern-fishes, lizard-fishes, and trout-perches, in which the affinity
is very remote. Probably these groups all have a common descent from
some primitive fish having an adipose fin, or at least a fleshy fold on
the back.

Of all the families of fishes, the one most interesting from almost
every point of view is that of the _Salmonidæ_, the salmon family. As
now restricted, it is not one of the largest families, as it comprises
less than a hundred species; but in beauty, activity, gaminess, quality
as food, and even in size of individuals, different members of the group
stand easily with the first among fishes. The following are the chief
external characteristics which are common to the members of the family:

Body oblong or moderately elongate, covered with cycloid, in scales of
varying size. Head naked. Mouth terminal or somewhat inferior, varying
considerably among the different species, those having the mouth largest
usually having also the strongest teeth. Maxillary provided with a
supplemental bone, and forming the lateral margin of the upper jaw.
Pseudobranchiæ present. Gill-rakers varying with the species. Opercula
complete. No barbels. Dorsal fin of moderate length, placed near the
middle of the length of the body. Adipose fin well developed. Caudal fin
forked. Anal fin moderate or rather long. Ventral fins nearly median in
position. Pectoral fins inserted low. Lateral line present. Outline of
belly rounded. Vertebræ in large number, usually about sixty.

The stomach in all the _Salmonidæ_ is siphonal, and at the pylorus are
many (15 to 200) comparatively large pyloric cœca. The air-bladder is
large. The eggs are usually much larger than in fishes generally, and
the ovaries are without special duct, the ova falling into the cavity of
the abdomen before exclusion. The large size of the eggs, their lack of
adhesiveness, and the readiness with which they may be impregnated,
render the _Salmonidæ_ peculiarly adapted for artificial culture.

The _Salmonidæ_ are peculiar to the north temperate and Arctic regions,
and within this range they are almost equally abundant wherever suitable
waters occur. Some of the species, especially the larger ones, are
marine and anadromous, living and growing in the sea, and ascending
fresh waters to spawn. Still others live in running brooks, entering
lakes or the sea when occasion serves, but not habitually doing so.
Still others are lake fishes, approaching the shore or entering brooks
in the spawning season, at other times retiring to waters of
considerable depth. Some of them are active, voracious, and gamy, while
others are comparatively defenseless and will not take the hook. They
are divisible into ten easily recognized genera: _Coregonus_,
_Argyrosomus_, _Brachymystax_, _Stenodus_, _Oncorhynchus_, _Salmo_,
_Hucho_, _Cristivomer_, _Salvelinus_, and _Plecoglossus_.

Fragments of fossil trout, very imperfectly known, are recorded chiefly
from Pleistocene deposits of Idaho, under the name of _Rhabdofario
lacustris_. We have also received from Dr. John C. Merriam, from
ferruginous sands of the same region, several fragments of jaws of
salmon, in the hook-nosed condition, with enlarged teeth, showing that
the present salmon-runs have been in operation for many thousands of
years. Most other fragments hitherto referred to _Salmonidæ_ belong to
some other kind of fish.

=Coregonus, the Whitefish.=—The genus _Coregonus_, which includes the
various species known in America as lake whitefish, is distinguishable
in general by the small size of its mouth, the weakness of its teeth,
and the large size of its scales. The teeth, especially, are either
reduced to slight asperities, or else are altogether wanting. The
species reach a length of one to three feet. With scarcely an exception
they inhabit clear lakes, and rarely enter streams except to spawn. In
far northern regions they often descend to the sea; but in the latitude
of the United States this is never possible for them, as they are unable
to endure warm or impure water. They seldom take the hook, and rarely
feed on other fishes. Numerous local varieties characterize the lakes of
Scandinavia, Scotland, and Arctic Asia and America. Largest and most
desirable of all these as a food-fish is the common whitefish of the
Great Lakes (_Coregonus clupeiformis_), with its allies or variants in
the Mackenzie and Yukon.

The species of _Coregonus_ differ from each other in the form and size
of the mouth, in the form of the body, and in the development of the
gill-rakers.

_Coregonus oxyrhynchus_—the _Schnäbel_ of Holland, Germany, and
Scandinavia—has the mouth very small, the sharp snout projecting far
beyond it. No species similar to this is found in America.

The Rocky Mountain whitefish (_Coregonus williamsoni_) has also a small
mouth and projecting snout, but the latter is blunter and much shorter
than in _C. oxyrhynchus_. This is a small species abounding everywhere
in the clear lakes and streams of the Rocky Mountains and the Sierra
Nevada, from Colorado to Vancouver Island. It is a handsome fish and
excellent as food.

[Illustration:

  FIG. 49.—Rocky Mountain Whitefish, _Coregonus williamsoni_ Girard.
]

Closely allied to _Coregonus williamsoni_ is the pilot-fish,
shad-waiter, roundfish, or Menomonee whitefish (_Coregonus
quadrilateralis_). This species is found in the Great Lakes, the
Adirondack region, the lakes of New Hampshire, and thence northwestward
to the Yukon, abounding in cold deep waters, its range apparently
nowhere coinciding with that of _Coregonus williamsoni_.

[Illustration:

  FIG. 50.—Whitefish, _Coregonus clupeiformis_ Mitchill. Ecorse, Mich.
]

The common whitefish (_Coregonus clupeiformis_) is the largest in size
of the species of _Coregonus_, and is unquestionably the finest as an
article of food. It varies considerably in appearance with age and
condition, but in general it is proportionately much deeper than any of
the other small-mouthed _Coregoni_. The adult fishes develop a
considerable fleshy hump at the shoulders, which causes the head, which
is very small, to appear disproportionately so. The whitefish spawns in
November and December, on rocky shoals in the Great Lakes. Its food was
ascertained by Dr. P. R. Hoy to consist chiefly of deep-water
crustaceans, with a few mollusks, and larvæ of water insects. "The
whitefish," writes Mr. James W. Milner, "has been known since the time
of the earliest explorers as preeminently a fine-flavored fish. In fact
there are few table-fishes its equal. To be appreciated in its fullest
excellence it should be taken fresh from the lake and broiled. Father
Marquette, Charlevoix, Sir John Richardson—explorers who for months at a
time had to depend upon the whitefish for their staple article of food—
bore testimony to the fact that they never lost their relish for it, and
deemed it a special excellence that the appetite never became cloyed
with it." The range of the whitefish extends from the lakes of New York
and New England northward to the Arctic Circle. The "Otsego bass" of
Otsego Lake in New York, celebrated by De Witt Clinton, is a local form
of the ordinary whitefish.

Allied to the American whitefish, but smaller in size, is the Lavaret,
Weissfisch, Adelfisch, or Weissfelchen (_Coregonus lavaretus_), of the
mountain lakes of Switzerland, Germany, and Sweden. _Coregonus
kennicotti_, the muksun, and _Coregonus nelsoni_, the humpback
whitefish, are found in northern Alaska and in the Yukon. Several other
related species occur in northern Europe and Siberia.

Another American species is the Sault whitefish, Lake Whiting or Musquaw
River whitefish (_Coregonus labradoricus_). Its teeth are stronger,
especially on the tongue, than in any of our other species, and its body
is slenderer than that of the whitefish. It is found in the upper Great
Lakes, in the Adirondack region, in Lake Winnipeseogee, and in the lakes
of Maine and New Brunswick. It is said to rise to the fly in the
Canadian lakes. This species runs up the St. Mary's River, from Lake
Huron to Lake Superior, in July and August. Great numbers are snared or
speared by the Indians at this season at the Sault Ste. Marie.

In the breeding season the scales are sometimes thickened or covered
with small warts, as in the male _Cyprinidæ_.

=Argyrosomus, the Lake Herring.=—In the genus _Argyrosomus_ the mouth is
larger, the premaxillary not set vertical, but extending forward on its
lower edge, and the body is more elongate and more evenly elliptical.
The species are more active and predaceous than those of _Coregonus_ and
are, on the whole, inferior as food.

The smallest and handsomest of the American whitefish is the cisco of
Lake Michigan (_Argyrosomus hoyi_). It is a slender fish, rarely
exceeding ten inches in length, and its scales have the brilliant
silvery luster of the mooneye and the ladyfish.

The lake herring, or cisco (_Argyrosomus artedi_), is, next to the
whitefish, the most important of the American species. It is more
elongate than the others, and has a comparatively large mouth, with
projecting under-jaw. It is correspondingly more voracious, and often
takes the hook. During the spawning season of the whitefish the lake
herring feeds on the ova of the latter, thereby doing a great amount of
mischief. As food this species is fair, but much inferior to the
whitefish. Its geographical distribution is essentially the same, but to
a greater degree it frequents shoal waters. In the small lakes around
Lake Michigan, in Indiana and Wisconsin (Tippecanoe, Geneva, Oconomowoc,
etc.), the cisco has long been established; and in these waters its
habits have undergone some change, as has also its external appearance.
It has been recorded as a distinct species, _Argyrosomus sisco_, and its
excellence as a game-fish has been long appreciated by the angler. These
lake ciscoes remain for most of the year in the depths of the lake,
coming to the surface only in search of certain insects, and to shallow
water only in the spawning season. This periodical disappearance of the
cisco has led to much foolish discussion as to the probability of their
returning by an underground passage to Lake Michigan during the periods
of their absence. One author, confounding "cisco" with "siscowet," has
assumed that this underground passage leads to Lake Superior, and that
the cisco is identical with the fat lake trout which bears the latter
name. The name "lake herring" alludes to the superficial resemblance
which this species possesses to the marine herring, a fish of quite a
different family.

[Illustration:

  FIG. 51.—Bluefin Cisco, _Argyrosomus nigripinnis_ Gill. Sheboygan.
]

Closely allied to the lake herring is the bluefin of Lake Michigan and
of certain lakes in New York (_Argyrosomus nigripinnis_), a fine large
species inhabiting deep waters, and recognizable by the blue-black color
of its lower fins. In the lakes of central New York are found two other
species, the so-called lake smelt (_Argyrosomus osmeriformis_) and the
long-jaw (_Argyrosomus_ _prognathus_). _Argyrosomus lucidus_ is abundant
in Great Bear Lake. In Alaska and Siberia are still other species of the
cisco type (_Argyrosomus laurettæ_, _A. pusillus_, _A. alascanus_); and
in Europe very similar species are the Scotch vendace (_Argyrosomus
vandesius_) and the Scandinavian Lok-Sild (lake herring), as well as
others less perfectly known.

The Tullibee, or "mongrel whitefish" (_Argyrosomus tullibee_), has a
deep body, like the shad, with the large mouth of the ciscoes. It is
found in the Great Lake region and northward, and very little is known
of its habits. A similar species (_Argyrosomus cyprinoides_) is recorded
from Siberia—a region which is peculiarly suited for the growth of the
_Coregoni_, but in which the species have never received much study.

=Brachymystax and Stenodus, the Inconnus.=—Another little-known form,
intermediate between the whitefish and the salmon, is _Brachymystax
lenock_, a large fish of the mountain streams of Siberia. Only the skins
brought home by Pallas a century ago are yet known. According to Pallas,
it sometimes reaches a weight of eighty pounds.

[Illustration:

  FIG. 52.—Inconnu, _Stenodus mackenziei_ (Richardson). Nulato, Alaska.
]

Still another genus, intermediate between the whitefish and the salmon,
is _Stenodus_, distinguished by its elongate body, feeble teeth, and
projecting lower jaw. The Inconnu, or Mackenzie River salmon, known on
the Yukon as "charr" (_Stenodus mackenziei_), belongs to this genus. It
reaches a weight of twenty pounds or more, and in the far north is a
food-fish of good quality. It runs in the Yukon as far as White Horse
Rapids. Not much is recorded of its habits, and few specimens exist in
museums. A species of _Stenodus_ called _Stenodus leucichthys_ inhabits
the Volga, Obi, Lena, and other northern rivers; but as yet little is
definitely known of the species.

=Oncorhynchus, the Quinnat Salmon.=—The genus _Oncorhynchus_ contains
the salmon of the Pacific. They are in fact, as well as in name, the
king salmon. The genus is closely related to _Salmo_, with which it
agrees in general as to the structure of its vomer, and from which it
differs in the increased number of anal rays, branchiostegals, pyloric
cœca, and gill-rakers. The character most convenient for distinguishing
_Oncorhynchus_, young or old, from all the species of _Salmo_, is the
number of developed rays in the anal fin. These in _Oncorhynchus_ are
thirteen to twenty, in _Salmo_ nine to twelve.

The species of _Oncorhynchus_ have long been known as anadromous salmon,
confined to the North Pacific. The species were first made known nearly
one hundred and fifty years ago by that most exact of early observers,
Steller, who, almost simultaneously with Krascheninnikov, another early
investigator, described and distinguished them with perfect accuracy
under their Russian vernacular names. These Russian names were, in 1792,
adopted by Walbaum as specific names in giving to these animals a
scientific nomenclature. Five species of _Oncorhynchus_ are well known
on both shores of the North Pacific, besides one other in Japan. These
have been greatly misunderstood by early observers on account of the
extraordinary changes due to differences in surroundings, in sex, and in
age, and in conditions connected with the process of reproduction.

There are five species of salmon (_Oncorhynchus_) in the waters of the
North Pacific, all found on both sides, besides one other which is known
only from the waters of Japan. These species may be called: (1) the
quinnat, or king-salmon, (2) the blue-back salmon, or redfish, (3) the
silver salmon, (4) the dog-salmon, (5) the humpback salmon, and (6) the
masu; or (1) _Oncorhynchus tschawytscha_, (2) _Oncorhynchus nerka_, (3)
_Oncorhynchus milktschitsch_, (4) _Oncorhynchus keta_, (5) _Oncorhynchus
gorbuscha_, (6) _Oncorhynchus masou_. All these species save the last
are now known to occur in the waters of Kamchatka, as well as in those
of Alaska and Oregon. These species, in all their varied conditions, may
usually be distinguished by the characters given below. Other
differences of form, color, and appearance are absolutely valueless for
distinction, unless specimens of the same age, sex, and condition are
compared.

The quinnat salmon (_Oncorhynchus tschawytscha_),[7] called quinnat,
tyee, chinook, or king-salmon, has an average weight of 22 pounds, but
individuals weighing 70 to 100 pounds are occasionally taken. It has
about 16 anal rays, 15 to 19 branchiostegals, 23 (9 + 14) gill-rakers on
the anterior gill-arch, and 140 to 185 pyloric cœca. The scales are
comparatively large, there being from 130 to 155 in a longitudinal
series. In the spring the body is silvery, the back, dorsal fin, and
caudal fin having more or less of round black spots, and the sides of
the head having a peculiar tin-colored metallic luster. In the fall the
color is often black or dirty red, and the species can then be
distinguished from the dog-salmon by its larger size and by its
technical characters. The flesh is rich and salmon-red, becoming
suddenly pale as the spawning season draws near.

Footnote 7:

  For valuable accounts of the habits of this species the reader is
  referred to papers by the late Cloudsley Rutter, ichthyologist of the
  _Albatross_, in the publications of the United States Fish Commission,
  the _Popular Science Monthly_, and the _Overland Monthly_.

[Illustration:

  FIG. 53.—Quinnat Salmon (female), _Oncorhynchus tschawytscha_
    (Walbaum). Columbia River.
]

[Illustration:

  FIG. 54.—King-salmon grilse, _Oncorhynchus tschawytscha_ (Walbaum).
    (Photograph by Cloudsley Rutter.)
]

[Illustration:

  FIG. 55.—Male Red Salmon in September, _Oncorhynchus nerka_ (Walbaum).
    Payette Lake, Idaho.
]

The blue-back salmon (_Oncorhynchus nerka_),[8] also called red salmon,
sukkegh, or sockeye, usually weighs from 5 to 8 pounds. It has about 14
developed anal rays, 14 branchiostegals, and 75 to 95 pyloric cœca. The
gill-rakers are more numerous than in any other salmon, the number being
usually about 39 (16 + 23). The scales are larger, there being 130 to
140 in the lateral line. In the spring the form is plumply rounded, and
the color is a clear bright blue above, silvery below, and everywhere
immaculate. Young fishes often show a few round black spots, which
disappear when they enter the sea. Fall specimens in the lakes are
bright crimson in color, the head clear olive-green, and they become in
a high degree hook-nosed and slab-sided, and bear little resemblance to
the spring run. Young spawning male grilse follow the changes which take
place in the adult, although often not more than half a pound in weight.
These little fishes often appear in mountain lakes, but whether they are
landlocked or have come up from the sea is still unsettled. These dwarf
forms, called kokos by the Indians and benimasu in Japan, form the
subspecies _Oncorhynchus nerka kennerlyi_. The flesh in this species is
firmer than that of any other and very red, of good flavor, though drier
and less rich than the king-salmon.

Footnote 8:

  For valuable records of the natural history of this species the reader
  is referred to various papers by Dr. Barton Warren Evermann in the
  Bulletins of the United States Fish Commission and elsewhere.

The silver salmon, or coho (_Oncorhynchus milktschitsch_, or _kisutch_),
reaches a weight of 5 to 8 pounds. It has 13 developed rays in the anal,
13 branchiostegals, 23 (10 + 13) gill-rakers, and 45 to 80 pyloric cœca.
There are about 127 scales in the lateral line. The scales are thin and
all except those of the lateral line readily fall off. This feature
distinguishes the species readily from the red salmon. In color it is
silvery in spring, greenish above, and with a few faint black spots on
the upper parts only. In the fall the males are mostly of a dirty red.
The flesh in this species is of excellent flavor, but pale in color, and
hence less valued than that of the quinnat and the red salmon.

The dog-salmon, calico salmon, or chum, called saké in Japan
(_Oncorhynchus keta_), reaches an average weight of about 7 to 10
pounds. It has about 14 anal rays, 14 branchiostegals, 24 (9 + 15)
gill-rakers, and 140 to 185 pyloric cœca. There are about 150 scales in
the lateral line. In spring it is dirty silvery, immaculate, or
sprinkled with small black specks, the fins dusky, the sides with faint
traces of gridiron-like bars. In the fall the male is brick-red or
blackish, and its jaws are greatly distorted. The pale flesh is well
flavored when fresh, but pale and mushy in texture and muddy in taste
when canned. It is said to take salt well, and great numbers of salt
dog-salmon are consumed in Japan.

The humpback salmon, or pink salmon (_Oncorhynchus gorbuscha_), is the
smallest of the American species, weighing from 3 to 5 pounds. It has
usually 15 anal rays, 12 branchiostegals, 28 (13 + 15) gill-rakers, and
about 180 pyloric cœca. Its scales are much smaller than in any other
salmon, there being 180 to 240 in the lateral line. In color it is
bluish above, silvery below, the posterior and upper parts with many
round black spots, the caudal fin always having a few large black spots
oblong in form. The males in fall are dirty red, and are more
extravagantly distorted than in any other of the _Salmonidæ_. The flesh
is softer than in the other species; it is pale in color, and, while of
fair flavor when fresh, is distinctly inferior when canned.

[Illustration:

  FIG. 56.—Humpback Salmon (female), _Oncorhynchus gorbuscha_ (Walbaum).
    Cook's Inlet.
]

The masu, or yezomasu (_Oncorhynchus masou_), is very similar to the
humpback, the scales a little larger, the caudal without black spots,
the back usually immaculate. It is one of the smaller salmon, and is
fairly abundant in the streams of Hokkaido, the island formerly known as
Yezo.

[Illustration:

  FIG 57.—Masu (female), _Oncorhynchus masou_ (Brevoort). Aomori, Japan.
]

Of these species the blue-back or red salmon predominates in Frazer
River and in most of the small rivers of Alaska, including all those
which flow from lakes. The greatest salmon rivers of the world are the
Nushegak and Karluk in Alaska, with the Columbia River, Frazer River,
and Sacramento River farther south. The red and the silver salmon
predominate in Puget Sound, the quinnat in the Columbia and the
Sacramento, and the silver salmon in most of the smaller streams along
the coast. All the species occur, however, from the Columbia northward;
but the blue-back is not found in the Sacramento. Only the quinnat and
the dog-salmon have been noticed south of San Francisco. In Japan _keta_
is by far the most abundant species of salmon. It is known as saké, and
largely salted and sold in the markets. _Nerka_ is known in Japan only
as landlocked in Lake Akan in northern Hokkaido. _Milktschitsch_ is
generally common, and with _masou_ is known as masu, or small salmon, as
distinguished from the large salmon, or saké. _Tschawytscha_ and
_gorbuscha_ are unknown in Japan. _Masou_ has not been found elsewhere.

The quinnat and blue-back salmon, the "noble salmon," habitually "run"
in the spring, the others in the fall. The usual order of running in the
rivers is as follows: _tschawytscha_, _nerka_, _milktschitsch_,
_gorbuscha_, _keta_. Those which run first go farthest. In the Yukon the
quinnat runs as far as Caribou Crossing and Lake Bennett, 2250 miles.
The red salmon runs to "Forty-Mile," which is nearly 1800 miles. Both
ascend to the head of the Columbia, Fraser, Nass, Skeena, Stikeen, and
Taku rivers. The quinnat runs practically only in the streams of large
size, fed with melting snows; the red salmon only in streams which pass
through lakes. It spawns only in small streams at the head of a lake.
The other species spawn in almost any fresh water and only close to the
sea.

The economic value of the spring-running salmon is far greater than that
of the other species, because they can be captured in numbers when at
their best, while the others are usually taken only after deterioration.

The habits of the salmon in the ocean are not easily studied. Quinnat
and silver salmon of all sizes are taken with the seine at almost any
season in Puget Sound and among the islands of Alaska. This would
indicate that these species do not go far from the shore. The silver
salmon certainly does not. The quinnat pursues the schools of herring.
It takes the hook freely in Monterey Bay, both near the shore and at a
distance of six to eight miles out. We have reason to believe that these
two species do not necessarily seek great depths, but probably remain
not very far from the mouth of the rivers in which they were spawned.
The blue-back or red salmon certainly seeks deeper water, as it is
seldom or never taken with the seine along shore, and it is known to
enter the Strait of Fuca in July, just before the running season,
therefore coming in from the open sea. The great majority of the quinnat
salmon, and probably all the blue-back salmon, enter the rivers in the
spring. The run of the quinnat begins generally at the last of March; it
lasts, with various modifications and interruptions, until the actual
spawning season in November, the greatest run being in early June in
Alaska, in July in the Columbia. The run begins earliest in the
northernmost rivers, and in the longest streams, the time of running and
the proportionate amount in each of the subordinate runs varying with
each different river. In general the runs are slack in the summer and
increase with the first high water of autumn. By the last of August only
straggling blue-backs can be found in the lower course of any stream;
but both in the Columbia and in the Sacramento the quinnat runs in
considerable numbers at least till October. In the Sacramento the run is
greatest in the fall, and more run in the summer than in spring. In the
Sacramento and the smaller rivers southward there is a winter run,
beginning in December. The spring quinnat salmon ascends only those
rivers which are fed by the melting snows from the mountains and which
have sufficient volume to send their waters well out to sea. Those
salmon which run in the spring are chiefly adults (supposed to be at
least three years old). Their milt and spawn are no more developed than
at the same time in others of the same species which have not yet
entered the rivers. It would appear that the contact with cold fresh
water, when in the ocean, in some way causes them to run towards it, and
to run before there is any special influence to that end exerted by the
development of the organs of generation. High water on any of these
rivers in the spring is always followed by an increased run of salmon.
The salmon-canners think—and this is probably true—that salmon which
would not have run till later are brought up by the contact with the
cold water. The cause of this effect of cold fresh water is not
understood. We may call it an instinct of the salmon, which is another
way of expressing our ignorance. In general it seems to be true that in
those rivers and during those years when the spring run is greatest the
fall run is least to be depended on.

The blue-back salmon runs chiefly in July and early August, beginning in
late June in Chilcoot River, where some were found actually spawning
July 15; beginning after the middle of July in Frazer River.

As the season advances, smaller and younger salmon of these species
(quinnat and blue-back) enter the rivers to spawn, and in the fall these
young specimens are very numerous. We have thus far failed to notice any
gradations in size or appearance of these young fish by which their ages
could be ascertained. It is, however, probable that some of both sexes
reproduce at the age of one year. In Frazer River, in the fall, quinnat
male grilse of every size, from eight inches upwards, were running, the
milt fully developed, but usually not showing the hooked jaws and dark
colors of the older males. Females less than eighteen inches in length
were not seen. All of either sex, large and small, then in the river had
the ovaries or milt developed. Little blue-backs of every size, down to
six inches, are also found in the upper Columbia in the fall, with their
organs of generation fully developed. Nineteen-twentieths of these young
fish are males, and some of them have the hooked jaws and red color of
the old males. Apparently all these young fishes, like the old ones, die
after spawning.

The average weight of the adult quinnat in the Columbia, in the spring,
is twenty-two pounds; in the Sacramento, about sixteen. Individuals
weighing from forty to sixty pounds are frequently found in both rivers,
and some as high as eighty or even one hundred pounds are recorded,
especially in Alaska, where the species tends to run larger. It is
questionable whether these large fishes are those which, of the same
age, have grown more rapidly; those which are older, but have for some
reason failed to spawn; or those which have survived one or more
spawning seasons. All these origins may be possible in individual cases.
There is, however, no positive evidence that any salmon of the Pacific
survives the spawning season.

Those fish which enter the rivers in the spring continue their ascent
till death or the spawning season overtakes them. Doubtless not one of
them ever returns to the ocean, and a large proportion fail to spawn.
They are known to ascend the Sacramento to its extreme head-waters,
about four hundred miles. In the Columbia they ascend as far as the
Bitter Root and Sawtooth mountains of Idaho, and their extreme limit is
not known. This is a distance of nearly a thousand miles. In the Yukon a
few ascend to Caribou Crossing and Lake Bennett, 2250 miles. At these
great distances, when the fish have reached the spawning grounds,
besides the usual changes of the breeding season their bodies are
covered with bruises, on which patches of white fungus (_Saprolegnia_)
develop. The fins become mutilated, their eyes are often injured or
destroyed, parasitic worms gather in their gills, they become extremely
emaciated, their flesh becomes white from the loss of oil; and as soon
as the spawning act is accomplished, and sometimes before, _all_ of them
die. The ascent of the Cascades and the Dalles of the Columbia causes
the injury or death of a great many salmon.

[Illustration:

  FIG. 58.—Red Salmon (mutilated dwarf male, after spawning),
    _Oncorhynchus nerka_ (Walbaum). Alturas Lake, Idaho.
]

When the salmon enter the river they refuse to take bait, and their
stomachs are always found empty and contracted. In the rivers they do
not feed; and when they reach the spawning grounds their stomachs,
pyloric cœca and all, are said to be no larger than one's finger. They
will sometimes take the fly, or a hook baited with salmon-roe, in the
clear waters of the upper tributaries, but this is apparently solely out
of annoyance, snapping at the meddling line. Only the quinnat and
blue-back (there called redfish) have been found at any great distance
from the sea, and these (as adult fishes) only in late summer and fall.

[Illustration:

  FIG. 59.—Young Male Quinnat Salmon, _Oncorhynchus tschawytscha_, dying
    after spawning. Sacramento River. (Photograph by Cloudsley Rutter.)
]

The spawning season is probably about the same for all the species. It
varies for each of the different rivers, and for different parts of the
same river. It doubtless extends from July to December, and takes place
usually as soon as the temperature of the water falls to 54°. The manner
of spawning is probably similar for all the species. In the quinnat the
fishes pair off; the male, with tail and snout, excavates a broad,
shallow "nest" in the gravelly bed of the stream, in rapid water, at a
depth of one to four feet and the female deposits her eggs in it. They
then float down the stream tail foremost, the only fashion in which
salmon descend to the sea. As already stated, in the head-waters of the
large streams, unquestionably, all die; it is the belief of the writer
that none ever survive. The young hatch in sixty days, and most of them
return to the ocean during the high water of the spring. They enter the
river as adults at the age of about four years.

The salmon of all kinds in the spring are silvery, spotted or not
according to the species, and with the mouth about equally symmetrical
in both sexes. As the spawning season approaches the female loses her
silvery color, becomes more slimy, the scales on the back partly sink
into the skin, and the flesh changes from salmon-red and becomes
variously paler, from the loss of oil; the degree of paleness varying
much with individuals and with inhabitants of different rivers. In the
Sacramento the flesh of the quinnat, in either spring or fall, is rarely
pale. In the Columbia a few with pale flesh are sometimes taken in
spring, and an increasing number from July on. In Frazer River the fall
run of the quinnat is nearly worthless for canning purposes, because so
many are "white-meated." In the spring very few are "white-meated"; but
the number increases towards fall, when there is every variation, some
having red streaks running through them, others being red toward the
head and pale toward the tail. The red and pale ones cannot be
distinguished externally, and the color is dependent on neither age nor
sex. There is said to be no difference in the taste, but there is little
market for canned salmon not of the conventional orange-color.

[Illustration:

  FIG. 60.—Quinnat Salmon, _Oncorhynchus tschawytscha_ (Walbaum).
    Monterey Bay. (Photograph by C. Rutter.)
]

As the season advances the difference between the males and females
becomes more and more marked, and keeps pace with the development of the
milt, as is shown by dissection. The males have (1) the premaxillaries
and the tip of the lower jaw more and more prolonged, both of the jaws
becoming finally strongly and often extravagantly hooked, so that either
they shut by the side of each other like shears, or else the mouth
cannot be closed. (2) The front teeth become very long and canine-like,
their growth proceeding very rapidly, until they are often half an inch
long. (3) The teeth on the vomer and tongue often disappear. (4) The
body grows more compressed and deeper at the shoulders, so that a very
distinct hump is formed; this is more developed in the humpback salmon,
but is found in all. (5) The scales disappear, especially on the back,
by the growth of spongy skin. (6) The color changes from silvery to
various shades of black and red, or blotchy, according to the species.
The blue-back turns rosy-red, the head bright olive; the dog-salmon a
dull red with blackish bars, and the quinnat generally blackish. The
distorted males are commonly considered worthless, rejected by the
canners and salmon-salters, but preserved by the Indians. These changes
are due solely to influences connected with the growth of the
reproductive organs. They are not in any way due to the action of fresh
water. They take place at about the same time in the adult males of all
species, whether in the ocean or in the rivers. At the time of the
spring runs all are symmetrical. In the fall all males, of whatever
species, are more or less distorted. Among the dog-salmon, which run
only in the fall, the males are hook-jawed and red-blotched when they
first enter the Strait of Fuca from the outside. The humpback, taken in
salt water about Seattle, have the same peculiarities. The male is
slab-sided, hook-billed, and distorted, and is rejected by the canners.
No hook-jawed females of any species have been seen.

On first entering a stream the salmon swim about as if playing. They
always head towards the current, and this appearance of playing may be
simply due to facing the moving tide. Afterwards they enter the deepest
parts of the stream and swim straight up, with few interruptions. Their
rate of travel at Sacramento is estimated by Stone at about two miles
per day; on the Columbia at about three miles per day. Those which enter
the Columbia in the spring and ascend to the mountain rivers of Idaho
must go at a more rapid rate than this, as they must make an average of
nearly four miles per day.

As already stated, the economic value of any species depends in great
part on its being a "spring salmon." It is not generally possible to
capture salmon of any species in large numbers until they have entered
the estuaries or rivers, and the spring salmon enter the large rivers
long before the growth of the organs of reproduction has reduced the
richness of the flesh. The fall salmon cannot be taken in quantity until
their flesh has deteriorated; hence the dog-salmon is practically almost
worthless except to the Indians, and the humpback salmon was regarded as
little better until comparatively recently, when it has been placed on
the market in cans as "Pink Salmon." It sells for about half the price
of the red salmon and one-third that of the quinnat. The red salmon is
smaller than the quinnat but, outside the Sacramento and the Columbia,
far more abundant, and at present it exceeds the quinnat in economic
value. The pack of red salmon in Alaska amounted in 1902 to over two
million cases (48 pounds each), worth wholesale about $4.00 per case, or
about $8,000,000. The other species in Alaska yield about one million
cases, the total wholesale value of the pack for 1902 being $8,667,673.
The aggregate value of the quinnat is considerably less, but either
species far exceed in value all other fishes of the Pacific taken
together. The silver salmon is found in the inland waters of Puget Sound
for a considerable time before the fall rains cause the fall runs, and
it may be taken in large numbers with seines before the season for
entering the rivers.

The fall salmon of all species, but especially of the dog-salmon, ascend
streams but a short distance before spawning. They seem to be in great
anxiety to find fresh water, and many of them work their way up little
brooks only a few inches deep, where they perish miserably, floundering
about on the stones. Every stream of whatever kind, from San Francisco
to Bering Sea, has more or less of these fall salmon.

The absence of the fine spring salmon in the streams of Japan is the
cause of the relative unimportance of the river fisheries of the
northern island of Japan, Hokkaido. It is not likely that either the
quinnat or the red salmon can be introduced into these rivers, as they
have no snow-fed streams, and few of them pass through lakes which are
not shut off by waterfalls. For the same reason neither of these species
is likely to become naturalized in the waters of our Eastern States,
though it is worth while to bring the red salmon to the St. Lawrence.
The silver salmon, already abundant in Japan, should thrive in the
rivers and bays of New England.

=The Parent-stream Theory.=—It has been generally accepted as
unquestioned by packers and fishermen that salmon return to spawn to the
very stream in which they were hatched. As early as 1880 the present
writer placed on record his opinion that this theory was unsound. In a
general way most salmon return to the parent stream, because when in the
sea the parent stream is the one most easily reached. The channels and
runways which directed their course to the sea may influence their
return trip in the same fashion. When the salmon is mature it seeks
fresh water. Other things being equal, about the same number will run
each year in the same channel. With all this, we find some curious
facts. Certain streams will have a run of exceptionally large or
exceptionally small red salmon. The time of the run bears some relation
to the length of the stream: those who have farthest to go start
earliest. The time of running bears also a relation to the temperature
of the spawning grounds: where the waters cool off earliest the fish run
soonest.

The supposed evidence in favor of the parent-stream theory may be
considered under three heads:[9] (1) Distinctive runs in various
streams. (2) Return of marked salmon. (3) Introduction of salmon into
new streams followed by their return.

Footnote 9:

  See an excellent article by H. S. Davis in the _Pacific Fisherman_ for
  July, 1903.

Under the first head it is often asserted of fishermen that they can
distinguish the salmon of different streams. Thus the Lynn Canal red
salmon are larger than those in most waters, and it is claimed that
those of Chilcoot Inlet are larger than those of the sister stream at
Chilcat. The red salmon of Red Fish Bay on Baranof Island are said to be
much smaller than usual, and those of the neighboring Necker Bay are not
more than one-third the ordinary size. Those of a small rapid stream
near Nass River are more wiry than those of the neighboring large
stream. The same claim is made for the different streams of Puget Sound,
each one having its characteristic run. In all this there is some truth
and perhaps some exaggeration. I have noticed that the Chilcoot fish
seem deeper in body than those at Chilcat. The red salmon becomes
compressed before spawning, and the Chilcoot fishes having a short run
spawn earlier than the Chilcat fishes, which have many miles to go, the
water being perhaps warmer at the mouth of the river. Perhaps some
localities may meet the nervous reactions of small fishes, while not
attracting the large ones. Mr. H. S. Davis well observes that "until a
constant difference has been demonstrated by a careful examination of
large numbers of fish from each stream taken _at the same time_, but
little weight can be attached to arguments of this nature."

It is doubtless true as a general proposition that nearly all salmon
return to the region in which they were spawned. Most of them apparently
never go far away from the mouth of the stream or the bay into which it
flows. It is true that salmon are occasionally taken well out at sea,
and it is certain that the red salmon runs of Puget Sound come from
outside the Straits of Fuca. There is, however, evidence that they
rarely go so far as that. When seeking shore they do not reach the
original channels.

In 1880 the writer, studying the salmon of the Columbia, used the
following words, which he has not had occasion to change:

"It is the prevailing impression that the salmon have some special
instinct which leads them to return to spawn in the same spawning
grounds where they were originally hatched. We fail to find any evidence
of this in the case of the Pacific-coast salmon, and we do not believe
it to be true. It seems more probable that the young salmon hatched in
any river mostly remain in the ocean within a radius of twenty, thirty,
or forty miles of its mouth. These, in their movements about in the
ocean, may come into contact with the cold waters of their parent
rivers, or perhaps of any other river, at a considerable distance from
the shore. In the case of the quinnat and the blue-back their 'instinct'
seems to lead them to ascend these fresh waters, and in a majority of
cases these waters will be those in which the fishes in question were
originally spawned. Later in the season the growth of the reproductive
organs leads them to approach the shore and search for fresh waters, and
still the chances are that they may find the original stream. But
undoubtedly many fall salmon ascend, or try to ascend, streams in which
no salmon was ever hatched. In little brooks about Puget Sound, where
the water is not three inches deep, are often found dead or dying salmon
which have entered them for the purpose of spawning. It is said of the
Russian River and other California rivers that their mouths, in the time
of low water in summer, generally become entirely closed by sand-bars,
and that the salmon, in their eagerness to ascend them, frequently fling
themselves entirely out of water on the beach. But this does not prove
that the salmon are guided by a marvelous geographical instinct which
leads them to their parent river in spite of the fact that the river
cannot be found. The waters of Russian River soak through these
sand-bars, and the salmon instinct, we think, leads them merely to
search for fresh waters. This matter is much in need of further
investigation; at present, however, we find no reason to believe that
the salmon enter the Rogue River simply because they were spawned there,
or that a salmon hatched in the Clackamas River is more likely, on that
account, to return to the Clackamas than to go up the Cowlitz or the Des
Chûtes."

Attempts have been made to settle this question by marking the fry. But
this is a very difficult matter indeed. Almost the only structure which
can be safely mutilated is the adipose fin, and this is often nipped off
by sticklebacks and other meddling fish. The following experiments have
been tried, according to Mr. Davis:

In March, 1896, 5000 king-salmon fry were marked by cutting off the
adipose fin, then set free in the Clackamas River. Nearly 400 of these
marked fish are said to have been taken in the Columbia in 1898, and a
few more in 1899. In addition a few were taken in 1898, 1899, and 1900
in the Sacramento River, but in much less numbers than in the Columbia.
In the Columbia most were taken at the mouth of the river, where nearly
all of the fishing was done, but a few were in the original stream, the
Clackamas. It is stated that the fry thus set free in the Clackamas came
from eggs obtained in the Sacramento—a matter which has, however, no
bearing on the present case.

In the Kalama hatchery on the Columbia River, Washington, 2000 fry of
the quinnat or king-salmon were marked in 1899 by a V-shaped notch in
the caudal fin. Numerous fishes thus marked were taken in the lower
Columbia in 1901 and 1902. A few were taken at the Kalama hatchery, but
some also at the hatcheries on Wind River and Clackamas River. At the
hatchery on Chehalis River six or seven were taken, the stream not being
a tributary of the Columbia, but flowing into Shoalwater Bay. None were
noticed in the Sacramento. The evidence shows that the most who are
hatched in a large stream tend to return to it, and that in general most
salmon return to the parent region. There is no evidence that a salmon
hatched in one branch of a river tends to return there rather than to
any other. Experiments of Messrs. Rutter and Spaulding in marking adult
fish at Karluk would indicate that they roam rather widely about the
island before spawning. An adult spawning fish, marked and set free at
Karluk, was taken soon after on the opposite side of the island of
Kadiak.

The introduction of salmon into new streams may throw some light on this
question. In 1897 and 1898 3,000,000 young quinnat-salmon fry were set
free in Papermill Creek near Olema, California. This is a small stream
flowing into the head of Tomales Bay, and it had never previously had a
run of salmon. In 1900, and especially in 1901, large quinnat salmon
appeared in considerable numbers in this stream. One specimen weighing
about sixteen pounds was sent to the present writer for identification.
These fishes certainly returned to the parent stream, although this
stream was one not at all fitted for their purpose.

But this may be accounted for by the topography of the bay. Tomales Bay
is a long and narrow channel, about twenty miles long and from one to
five in width, isolated from other rivers and with but one tributary
stream. Probably the salmon had not wandered far from it; some may not
have left it at all. In any event, a large number certainly came back to
the same place.

That the salmon rarely go far away is fairly attested. Schools of
king-salmon play in Monterey Bay, and chase the herring about in the
channels of southeastern Alaska. A few years since Captain J. F. Moser,
in charge of the _Albatross_, set gill-nets for salmon at various places
in the sea off the Oregon and Washington coast, catching none except in
the bays.

Mr. Davis gives an account of the liberation of salmon in Chinook River,
which flows into the Columbia at Baker's Bay:

"It is a small, sluggish stream and has never been frequented by Chinook
salmon, although considerable numbers of silver and dog salmon enter it
late in the fall. A few years ago the State established a hatchery on
this stream, and since 1898 between 1,000,000 and 2,000,000 Chinook fry
have been turned out here annually. The fish are taken from the
pound-nets in Baker's Bay, towed into the river in crates and then
liberated above the dike, which prevents their return to the Columbia.
When ripe the salmon ascend to the hatchery, some two or three miles
farther up the river, where they are spawned.

"The superintendent of the hatchery, Mr. Hansen, informs me that in
1902, during November and December, quite a number of Chinook salmon
ascended the Chinook River. About 150 salmon of both sexes were taken in
a trap located in the river about four miles from its mouth. At first
thought it would appear that these were probably fish which, when fry,
had been liberated in the river, but unfortunately there is no proof
that this was the case. According to Mr. Hansen, the season of 1902 was
remarkable in that the salmon ran inshore in large schools, a thing
which they had not done before for years. It is possible that the fish,
being forced in close to the shore, came in contact with the current
from the Chinook River, which, since the stream is small and sluggish,
would not be felt far from shore. Once brought under the influence of
the current from the river, the salmon would naturally ascend that
stream, whether they had been hatched there or not."

The general conclusion, apparently warranted by the facts at hand, is
that salmon, for the most part, do not go to a great distance from the
stream in which they are hatched, that most of them return to the
streams of the same region, a majority to the parent stream, but that
there is no evidence that they choose the parental spawning grounds in
preference to any other, and none that they will prefer an undesirable
stream to a favorable one for the reason that they happen to have been
hatched in the former.

=The Jadgeska Hatchery.=—Mr. John C. Callbreath of Wrangel, Alaska, has
long conducted a very interesting but very costly experiment in this
line. About 1890 he established himself in a small stream called
Jadgeska on the west coast of Etolin Island, tributary to McHenry Inlet,
Clarence Straits. This stream led from a lake, and in it a few thousand
red salmon spawned, besides multitudes of silver salmon, dog-salmon, and
humpback salmon. Making a dam across the stream, he helped the red
salmon over it, destroying all of the inferior kinds which entered the
stream. He also established a hatchery for the red salmon, turning loose
many fry yearly for ten or twelve years. This was done in the
expectation that all the salmon hatched would return to Jadgeska in
about four years. By destroying all individuals of other species
attempting to run, it was expected that they would become extinct so far
as the stream is concerned.

The result of this experiment has been disappointment. After twelve
years or more there has been no increase of red salmon in the stream,
and no decrease of humpbacks and other humbler forms of salmon. Mr.
Callbreath draws the conclusion that salmon run at a much greater age
than has been supposed—at the age of sixteen years, perhaps, instead of
four. A far more probable conclusion is that his salmon have joined
other bands bound for more suitable streams. It is indeed claimed that
since the establishment of Callbreath's hatchery on Etolin Island there
has been a notable increase of the salmon run in the various streams of
Prince of Wales Island on the opposite side of Clarence Straits. But
this statement, while largely current among the cannerymen, and not
improbable, needs verification.

We shall await with much interest the return of the thousands of salmon
hatched in 1902 in Naha stream. We may venture the prophecy that while a
large percentage will return to Loring, many others will enter Yes Bay,
Karta Bay, Moira Sound, and other red salmon waters along the line of
their return from Dixon Entrance or the open sea.

=Salmon-packing.=—The canning of salmon, that is, the packing of the
flesh in tin cases, hermetically sealed after boiling, was begun on the
Columbia River by the Hume Brothers in 1866. In 1874 canneries were
established on the Sacramento River, in 1876 on Puget Sound and on
Frazer River, and in 1878 in Alaska. At first only the quinnat salmon
was packed; afterwards the red salmon and the silver salmon, and finally
the humpback, known commercially as pink salmon. In most cases the flesh
is packed in one-pound tins, forty-eight of which constitute a case. The
wholesale price in 1903 was for quinnat salmon $5.60 per case, red
salmon $4.00, silver salmon $2.60, humpback salmon $2.00, and dog-salmon
$1.50. It costs in round numbers $2.00 to pack a case of salmon. The
very low price of the inferior brands is due to overproduction.

The output of the salmon fishery of the Pacific coast amounts to about
fifteen millions per year, that of Alaska constituting seven to nine
millions of this amount. Of this amount the red salmon constitutes
somewhat more than half, the quinnat about four-fifths of the rest.

In almost all salmon streams there is evidence of considerable
diminution in numbers, although the evidence is sometimes conflicting.
In Alaska this has been due to the vicious custom, now done away with,
of barricading the streams so that the fish could not reach the spawning
grounds, but might be all taken with the net. In the Columbia River the
reduction in numbers is mainly due to stationary traps and
salmon-wheels, which leave the fish relatively little chance to reach
the spawning grounds. In years of high water doubtless many salmon run
in the spring which might otherwise have waited until fall.

The key to the situation lies in the artificial propagation of salmon by
means of well-ordered hatcheries. By this means the fisheries of the
Sacramento have been fully restored, those of the Columbia approximately
maintained, and a hopeful beginning has been made in hatching red salmon
in Alaska.



                               CHAPTER V
                        SALMONIDÆ—(_Continued_)


=SALMO, the Trout and Atlantic Salmon.=—The genus _Salmo_ comprises
those forms of salmon which have been longest known. As in related
genera, the mouth is large, and the jaws, palatines, and tongue are
armed with strong teeth. The vomer is flat, its shaft not depressed
below the level of the head or chevron (the anterior end). There are a
few teeth on the chevron; and behind it, on the shaft, there is either a
double series of teeth or an irregular single series. These teeth in the
true salmon disappear with age, but in the others (the black-spotted
trout) they are persistent. The scales are silvery and moderate or small
in size. There are 9 to 11 developed rays in the anal fin. The caudal
fin is truncate, or variously concave or forked. There are usually 40 to
70 pyloric cœca, 11 or 12 branchiostegals, and about 20 (8 + 12)
gill-rakers. The sexual peculiarities are in general less marked than in
_Oncorhynchus_; they are also greater in the anadromous species than in
those which inhabit fresh waters. In general the male in the breeding
season is redder, its jaws are prolonged, the front teeth enlarged, the
lower jaw turned upwards at the end, and the upper jaw notched, or
sometimes even perforated, by the tip of the lower. All the species of
_Salmo_ (like those of _Oncorhynchus_) are more or less spotted with
black. Unlike the species of _Oncorhynchus_, the species of _Salmo_ feed
more or less while in fresh water, and the individuals for the most part
do not die after spawning, although many old males do thus perish.

=The Atlantic Salmon.=—The large species of _Salmo_, called salmon by
English-speaking people (_Salmo salar_, _Salmo trutta_), are marine and
anadromous, taking the place in the North Atlantic occupied in the North
Pacific by the species of _Oncorhynchus_. Two others more or less
similar in character occur in Japan and Kamchatka. The others (trout),
forming the subgenus _Salar_, are non-migratory, or at least irregularly
or imperfectly anadromous. The true or black-spotted trout abound in all
streams of northern Europe, northern Asia, and in that part of North
America which lies _west_ of the Mississippi Valley. The black-spotted
trout are entirely wanting in eastern America—a remarkable fact in
geographical distribution, perhaps explained only on the hypothesis of
the comparatively recent and Eurasiatic origin of the group, which, we
may suppose, has not yet had opportunity to extend its range across the
plains, unsuitable for salmon life, which separate the upper Missouri
from the Great Lakes.

The salmon (_Salmo salar_) is the only black-spotted salmonoid found in
American waters tributary to the Atlantic. In Europe, where other
species similarly colored occur, the species may be best distinguished
by the fact that the teeth on the shaft of the vomer mostly disappear
with age. From the only other species positively known, the salmon trout
(_Salmo trutta_), which shares this character, the true salmon may be
distinguished by the presence of but eleven scales between the adipose
fin and the lateral line, while _Salmo trutta_ has about fourteen. The
scales are comparatively large in the salmon, there being about one
hundred and twenty-five in the lateral line. The caudal fin, which is
forked in the young, becomes, as in other species of salmon, more or
less truncate with age. The pyloric cœca are fifty to sixty in number.

The color in adults, according to Dr. Day, is "superiorly of a
steel-blue, becoming lighter on the sides and beneath. Mostly a few
rounded or X-shaped spots scattered above the lateral line and upper
half of the head, being more numerous in the female than in the male.
Dorsal, caudal, and pectoral fins dusky; ventrals and anal white, the
former grayish internally. Prior to entering fresh waters these fish are
of a brilliant steel-blue along the back, which becomes changed to a
muddy tinge when they enter rivers. After these fish have passed into
the fresh waters for the purpose of breeding, numerous orange streaks
appear in the cheeks of the male, and also spots or even marks of the
same, and likewise of a red color, on the body. It is now termed a
'redfish.' The female, however, is dark in color and known as
'blackfish.' 'Smolts' (young river fish) are bluish along the upper half
of the body, silvery along the sides, due to a layer of silvery scales
being formed over the trout-like colors, while they have darker fins
than the yearling 'ping,' but similar bands and spots, which can be seen
(as in the parr) if the example be held in certain positions of light.
'Parr' (fishes of the year) have two or three black spots only on the
opercle, and black spots and also orange ones along the upper half of
the body, and no dark ones below the lateral line, although there may be
orange ones which can be seen in its course. Along the side of the body
are a series (12 to 15) of transverse bluish bands, wider than the
ground color and crossing the lateral line, while in the upper half of
the body the darker color of the back forms an arch over each of these
bands, a row of spots along the middle of the rayed dorsal fin, and the
adipose orange-tipped."

The dusky cross-shades found in the young salmon or parr are
characteristic of the young of salmon, trout, grayling, and nearly all
the other _Salmonidæ_.

The salmon of the Atlantic is, as already stated, an anadromous fish,
spending most of its life in the sea, and entering the streams in the
fall for the purpose of reproduction. The time of running varies much in
different streams and also in different countries. As with the Pacific
species, these salmon are not easily discouraged in their progress,
leaping cascades and other obstructions, or, if these prove impassable,
dying after repeated fruitless attempts.

The young salmon, known as the "parr," is hatched in the spring. It
usually remains about two years in the rivers, descending at about the
third spring to the sea, when it is known as "smolt." In the sea it
grows much more rapidly, and becomes more silvery in color, and is known
as "grilse." The grilse rapidly develop into the adult salmon; and some
of them, as in the case with the grilse of the Pacific salmon, are
capable of reproduction.

After spawning the salmon are very lean and unwholesome in appearance,
as in fact. They are then known as "kelts." The Atlantic salmon does not
ascend rivers to any such distances as those traversed by the quinnat
and the blue-back. Its kelts, therefore, for the most part survive the
act of spawning. Dr. Day thinks that they feed upon the young salmon in
the rivers, and that, therefore, the destruction of the kelts might
increase the supply of salmon.

As a food-fish the Atlantic salmon is very similar to the quinnat
salmon, neither better nor worse, so far as I can see, when equally
fresh. In both the flesh is rich and finely flavored; but the appetite
of man becomes cloyed with salmon-flesh sooner than with that of
whitefish, smelt, or charr. In size the Atlantic salmon does not fall
far short of the quinnat. The average weight of the adult is probably
less than fifteen pounds. The largest one of which I find a record was
taken on the coast of Ireland in 1881, and weighed 84¾ pounds.

The salmon is found in Europe between the latitude of 45° and 75°. In
the United States it is now rarely seen south of Cape Cod, although
formerly the Hudson and numerous other rivers were salmon-streams.
Overfishing, obstructions in the rivers, and pollution of the water by
manufactories and by city sewage are agencies against which the salmon
cannot cope.

Seven species of salmon (as distinguished from trout) are recognized by
Dr. Günther in Europe, and three in America. The landlocked forms,
abundant in Norway, Sweden, and Maine, which cannot, or at least do not,
descend to the sea, are regarded by him as distinct species. "The
question," observes Dr Günther, "whether any of the migratory species
can be retained by artificial means in fresh water, and finally
accommodate themselves to a permanent sojourn therein, must be negatived
for the present." On this point I think that the balance of evidence
leads to a different conclusion. These fresh-water forms (_Sebago_ and
_Ouananiche_) are actually salmon which have become landlocked. I have
compared numerous specimens of the common landlocked salmon (_Salmo
salar sebago_) of the lakes of Maine and New Brunswick with landlocked
salmon (_Salmo salar hardini_) from the lakes of Sweden, and with
numerous migratory salmon, both from America and Europe. I see no reason
for regarding them as specifically distinct. The differences are very
trivial in kind, and not greater than would be expected on the
hypothesis of recent adaptation of the salmon to lake life. We have
therefore on our Atlantic coast but one species of salmon, _Salmo
salar_. The landlocked form of the lakes of Maine is _Salmo salar
sebago_. The _Ouananiche_ of Lake St. John and the Saguenay, beloved of
anglers, is _Salmo salar ouananiche_.

=The Ouananiche.=—Dr. Henry Van Dyke writes thus of the _Ouananiche_:
"But the prince of the pool was the fighting _Ouananiche_, the little
salmon of St. John. Here let me chant thy praise, thou noblest and most
high-minded fish, the cleanest feeder, the merriest liver, the loftiest
leaper, and the bravest warrior of all creatures that swim! Thy cousin,
the trout, in his purple and gold with crimson spots, wears a more
splendid armor than thy russet and silver mottled with black, but thine
is the kinglier nature.

"The old salmon of the sea who begat thee long ago in these inland
waters became a backslider, descending again to the ocean, and grew
gross and heavy with coarse feeding. But thou, unsalted salmon of the
foaming floods, not landlocked as men call thee, but choosing of thine
own free will to dwell on a loftier level in the pure, swift current of
a living stream, hath grown in grace and risen to a better life.

"Thou art not to be measured by quantity but by quality, and thy five
pounds of pure vigor will outweigh a score of pounds of flesh less
vitalized by spirit. Thou feedest on the flies of the air, and thy food
is transformed into an aerial passion for flight, as thou springest
across the pool, vaulting toward the sky. Thine eyes have grown large
and keen by piercing through the foam, and the feathered hook that can
deceive thee must be deftly tied and delicately cast. Thy tail and fins,
by ceaseless conflict with the rapids, have broadened and strengthened,
so that they can flash thy slender body like a living arrow up the fall.
As Launcelot among the knights, so art thou among the fish, the
plain-armored hero, the sunburnt champion of all the water-folk."

Dr. Francis Day, who has very thoroughly studied these fishes, takes, in
his memoir on "The Fishes of Great Britain and Ireland," and in other
papers, a similar view in regard to the European species. Omitting the
species with permanent teeth on the shaft of the vomer (subgenus
_Salar_), he finds among the salmon proper only two species, _Salmo
salar_ and _Salmo trutta_. The latter species, the sea-trout or
salmon-trout of England and the estuaries of northern Europe, is similar
to the salmon in many respects, but has rather smaller scales, there
being fourteen in an oblique series between the adipose fin and the
lateral line. It is not so strong a fish as the salmon, nor does it
reach so large a size. Although naturally anadromous, like the true
salmon, landlocked forms of the salmon-trout are not uncommon. These
have been usually regarded as different species, while aberrant or
intermediate individuals are usually regarded as hybrids. The
salmon-trout of Europe have many analogies with the steelhead of the
Pacific.

The present writer has examined many thousands of American _Salmonidæ_,
both of _Oncorhynchus_ and _Salmo_. While many variations have come to
his attention, and he has been compelled more than once to modify his
views as to specific distinctions, he has never yet seen an individual
which he had the slightest reason to regard as a "hybrid." It is
certainly illogical to conclude that every specimen which does not
correspond to our closet-formed definition of its species must therefore
be a "hybrid" with some other. There is no evidence worth mentioning,
known to me, of extensive hybridization in a state of nature in any
group of fishes. This matter is much in need of further study; for what
is true of the species in one region, in this regard, may not be true of
others. Dr. Günther observes:

"Johnson, a correspondent of Willughby, had already expressed his belief
that the different salmonoids interbreed; and this view has since been
shared by many who have observed these fishes in nature. Hybrids between
the sewin (_Salmo trutta cambricus_) and the river-trout (_Salmo fario_)
were numerous in the Rhymney and other rivers of South Wales before
salmonoids were almost exterminated by the pollutions allowed to pass
into these streams, and so variable in their characters that the passage
from one species to the other could be demonstrated in an almost
unbroken series, which might induce some naturalists to regard both
species as identical. Abundant evidence of a similar character has
accumulated, showing the frequent occurrence of hybrids between _Salmo
fario_ and _S. trutta_.... In some rivers the conditions appear to be
more favorable to hybridism than in others in which hybrids are of
comparatively rare occurrence. Hybrids between the salmon and other
species are very scarce everywhere."

Very similar to the European _Salmo trutta_ is the trout of Japan
(_Salmo perryi_), the young called yamabe, the adult kawamasu, or
river-salmon. This species abounds everywhere in Japan, the young being
the common trout of the brooks, black-spotted and crossed by parr-marks,
the adult reaching a weight of ten or twelve pounds in the larger rivers
and descending to the sea. In Kamchatka is another large, black-spotted,
salmon-like species properly to be called a salmon-trout. This is _Salmo
mykiss_, a name very wrongly applied to the cutthroat trout of the
Columbia.

The black-spotted trout, forming the subgenus _Salar_, differ from
_Salmo salar_ and _Salmo trutta_ in the greater development of the
vomerine teeth, which are persistent throughout life, in a long double
series on the shaft of the vomer. About seven species are laboriously
distinguished by Dr. Günther in the waters of western Europe. Most of
these are regarded by Dr. Day as varieties of _Salmo fario_. The latter
species, the common river-trout or lake-trout of Europe, is found
throughout northern and central Europe, wherever suitable waters occur.
It is abundant, gamy, takes the hook readily, and is excellent as food.
It is more hardy than the different species of charr, although from an
æsthetic point of view it must be regarded as inferior to all of the
_Salvelini_. The largest river-trout recorded by Dr. Day weighed
twenty-one pounds. Such large individuals are usually found in lakes in
the north, well stocked with smaller fishes on which trout may feed.
Farther south, where the surroundings are less favorable to trout-life,
they become mature at a length of less than a foot, and a weight of a
few ounces. These excessive variations in the size of individuals have
received too little notice from students of _Salmonidæ_. Similar
variations occur in all the non-migratory species of _Salmo_ and of
_Salvelinus_. Numerous river-trout have been recorded from northern
Asia, but as yet nothing can be definitely stated as to the number of
species actually existing.

=The Black-spotted Trout.=—In North America only the region west of the
Mississippi Valley, the streams of southeastern Alaska, and the valley
of Mackenzie River have species of black-spotted trout. There are few of
these north of Sitka in Alaska, although black-spotted trout are
occasionally taken on Kadiak and about Bristol Bay, and none east of the
Rocky Mountain region. If we are to follow the usage of the names
"salmon" and "trout" which prevails in England, we should say that, in
America, it is only these western regions which have any trout at all.
Of the number of species (about twenty-five in all) which have been
indicated by authors, certainly not more than about 8 to 10 can possibly
be regarded as distinct species. The other names are either useless
synonyms, or else they have been applied to local varieties which pass
by degrees into the ordinary types.

=The Trout of Western America.=—In the western part of America are found
more than a score of forms of trout of the genus _Salmo_, all closely
related and difficult to distinguish. There are representatives in the
head-waters of the Rio Grande, Arkansas, South Platte, Missouri, and
Colorado rivers; also in the Great Salt Lake basin, throughout the
Columbia basin, in all suitable waters from southern California and
Chihuahua to Sitka, and even to Bristol Bay, similar forms again
appearing in Kamchatka and Japan.

Among the various more or less tangible species that may be recognized,
three distinct series appear. These have been termed the cutthroat-trout
series (allies of _Salmo clarkii_), the rainbow-trout series (allies of
_Salmo irideus_), and the steelhead series (allies of _Salmo rivularis_,
a species more usually but wrongly called _Salmo gairdneri_).

The steelhead, or _rivularis_ series, is found in the coastwise streams
of California and in the streams of Oregon and Washington, below the
great Shoshone Falls of Snake River, and northward in Alaska along the
mainland as far as Skaguay. The steelhead-trout reach a large size (10
to 20 pounds). They spend a large part of their life in the sea. In all
the true steelheads the head is relatively very short, its length being
contained about five times in the distance from tip of snout to base of
caudal fin. The scales in the steelhead are always rather small, about
150 in a linear series, and there is no red under the throat. The spots
on the dorsal fin are fewer in the steelhead (4 to 6 rows) than in the
other American trout.

The rainbow forms are chiefly confined to the streams of California and
Oregon. In these the scales are large (about 135 in a lengthwise series)
and the head is relatively large, forming nearly one-fourth of the
length to base of caudal. These enter the sea only when in the small
coastwise streams. Usually they have no red under the throat. The
cutthroat forms are found from Humboldt Bay northward as far as Sitka,
in the coastwise streams of northern California, Oregon, Washington, and
Alaska, and all the clear streams on both sides of the Rocky Mountains,
and in the Great Basin and the head-waters of the Colorado. The
cutthroat-trout have the scales small, about 180, and there is always a
bright dash of orange-red on each side concealed beneath the branches of
the lower jaw. Along the western slope of the Sierra Nevada there are
also forms of trout with the general appearance of rainbow-trout and
evidently belonging to that species, but with scales intermediate in
number (in McCloud River), var. _shasta_, or with scales as small as in
the typical cutthroat (Kern River), var. _gilberti_. In these
small-scaled forms more or less red appears below the lower jaw, and
they are doubtless what they appear to be, really intermediate between
_clarkii_ and _irideus_, although certainly nearest the latter. A
similar series of forms occurs in the Columbia basin, the upper Snake
being inhabited by _clarkii_ and the lower Snake by _clarkii_ and
_rivularis_, together with a medley of forms apparently intermediate.

It seems probable that the American trout originated in Asia, extended
its range to southeast Alaska, thence southward to the Fraser and
Columbia, thence to the Yellowstone and the Missouri _via_ Two-Ocean
Pass; from the Snake River to the Great Basins of Utah and Nevada; from
the Missouri southward to the Platte and the Arkansas, thence from the
Platte to the Rio Grande and the Colorado, and then from Oregon
southward coastwise and along the Sierras to northern Mexico, thence
northward and coastwise, the sea-running forms passing from stream to
stream.

[Illustration:

  FIG. 61.—Rainbow Trout (male), _Salmo irideus shasta_ Jordan.
    (Photograph by Cloudsley Rutter.)
]

Of the American species the rainbow trout of California (_Salmo
irideus_) most nearly approaches the European _Salmo fario_. It has the
scales comparatively large, although rather smaller than in _Salmo
fario_, the usual number in a longitudinal series being about 135. The
mouth is smaller than in other American trout; the maxillary, except in
old males, rarely extending beyond the eye. The caudal fin is well
forked, becoming in very old fishes more nearly truncate. The head is
relatively large, about four times in the total length. The size of the
head forms the best distinctive character. The color, as in all the
other species, is bluish, the sides silvery in the males, with a red
lateral band, and reddish and dusky blotches. The head, back, and upper
fins are sprinkled with round black spots, which are very variable in
number, those on the dorsal usually in about nine rows. In specimens
taken in the sea this species, like most other trout in similar
conditions, is bright silvery, and sometimes immaculate. This species is
especially characteristic of the waters of California. It abounds in
every clear brook, from the Mexican line northward to Mount Shasta, or
beyond, the species passing in the Columbia region by degrees into the
species or form known as _Salmo masoni_, the Oregon rainbow trout, a
small rainbow trout common in the forest streams of Oregon, with smaller
mouth and fewer spots on the dorsal. No true rainbow trout have been
anywhere obtained to the eastward of the Cascade Range or of the Sierra
Nevada, except as artificially planted in the Truckee River. The species
varies much in size; specimens from northern California often reach a
weight of six pounds, while in the streams above Tia Juana in Lower
California the southernmost locality from which I have obtained trout,
they seldom exceed a length of six inches. Although not usually an
anadromous species, the rainbow trout frequently moves about in the
rivers, and it often enters the sea, large sea-run specimens being often
taken for steelheads. Several attempts have been made to introduce it in
Eastern streams, but it appears to seek the sea when it is lost. It is
apparently more hardy and less greedy than the American charr, or
brook-trout (_Salvelinus fontinalis_). On the other hand, it is
distinctly inferior to the latter in beauty and in gaminess.

[Illustration:

  FIG. 62.—Rainbow Trout (female), _Salmo irideus shasta_ Jordan.
    (Photograph by Cloudsley Rutter.)
]

Three varieties of some importance have been indicated, _Salmo irideus
stonei_, the Nissui trout of the Klamath, with spots on the posterior
parts only, _Salmo irideus shasta_ of the upper Sacramento, and the
small-scaled _Salmo irideus gilberti_ of the Kings and Kern rivers. In
the head-waters of the Kern, in a stream called Volcano Creek or Whitney
Creek, the waterfall sometimes called Agua-Bonita shuts off the
movements of the trout. Above this fall is a dwarf form with bright
golden fins, and the scales scarcely imbricated. This is the "golden
trout of Mount Whitney," _Salmo irideus agua-bonita_. It will possibly
be found to change back to the original type if propagated in different
waters.

In beauty of color, gracefulness of form and movement, sprightliness
when in the water, reckless dash with which it springs from the water to
meet the descending fly ere it strikes the surface, and the mad and
repeated leaps from the water when hooked, the rainbow trout must ever
hold a very high rank. "The gamest fish we have ever seen," writes Dr.
Evermann, "was a 16-inch rainbow taken on a fly in a small spring branch
tributary of Williamson River in southern Oregon. It was in a broad and
deep pool of exceedingly clear water. As the angler from behind a clump
of willows made the cast the trout bounded from the water and met the
fly in the air a foot or more above the surface; missing it, he dropped
upon the water, only to turn about and strike viciously a second time at
the fly just as it touched the surface; though he again missed the fly,
the hook caught him in the lower jaw from the outside, and then began a
fight which would delight the heart of any angler. His first effort was
to reach the bottom of the pool, then, doubling upon the line, he made
three jumps from the water in quick succession, clearing the surface in
each instance from one to four feet, and every time doing his utmost to
free himself from the hook by shaking his head as vigorously as a dog
shakes a rat. Then he would rush wildly about in the large pool, now
attempting to go down over the riffle below the pool, now trying the
opposite direction, and often striving to hide under one or the other of
the banks. It was easy to handle the fish when the dash was made up or
down stream or for the opposite side, but when he turned about and made
a rush for the protection of the overhanging bank upon which the angler
stood it was not easy to keep the line taut. Movements such as these
were frequently repeated, and two more leaps were made. But finally he
was worn out after as honest a fight as trout ever made."

"The rainbow takes the fly so readily that there is no reason for
resorting to grasshoppers, salmon-eggs, or other bait. It is a fish
whose gaminess will satisfy the most exacting of expert anglers and
whose readiness to take any proper line will please the most impatient
of inexperienced amateurs."

The steelhead (_Salmo rivularis_) is a large trout, reaching twelve to
twenty pounds in weight, found abundantly in river estuaries and
sometimes in lakes from Lynn Canal to Santa Barbara. The spent fish
abound in the rivers in spring at the time of the salmon-run. The
species is rarely canned, but is valued for shipment in cold storage.
Its bones are much more firm than those of the salmon—a trait
unfavorable for canning purposes. The flesh when not spent after
spawning is excellent. The steelhead does not die after spawning, as all
the Pacific salmon do.

[Illustration:

  FIG. 63.—Steelhead Trout, _Salmo rivularis_ Ayres. Columbia River.
]

It is thought by some anglers that the young fish hatched in the brooks
from eggs of the steelhead remain in mountain streams from six to
thirty-six months, going down to the sea with the high waters of spring,
after which they return to spawn as typical steelhead trout. I now
regard this view as unfounded. In my experience the rainbow and the
steelhead are always distinguishable: the steelhead abounds where the
rainbow trout is unknown; the scales in the steelhead are always smaller
(about 155) than in typical rainbow trout; finally, the small size of
the head in the steelhead is always distinctive.

The Kamloops trout, described by the writer from the upper Columbia,
seems to be a typical steelhead as found well up the rivers away from
the sea. Derived from the steelhead, but apparently quite distinct from
it, are three very noble trout, all confined so far as yet known to Lake
Crescent in northwestern Washington. These are the crescent trout,
_Salmo crescentis_, the Beardslee trout, _Salmo beardsleei_, and the
long-headed trout, _Salmo bathæcetor_. The first two, discovered by
Admiral L. A. Beardslee, are trout of peculiar attractiveness and
excellence. The third is a deep-water form, never rising to the surface,
and caught only on set lines. Its origin is still uncertain, and it may
be derived from some type other than the steelhead.

=Cutthroat or Red-throated Trout.=—This species has much smaller scales
than the rainbow trout or steelhead, the usual number in a longitudinal
series being 160 to 170. Its head is longer (about four times in length
to base of caudal). Its mouth is proportionately larger, and there is
always a narrow band of small teeth on the hyoid bone at the base of the
tongue. These teeth are always wanting in _Salmo irideus_ and
_rivularis_ in which species the rim of the tongue only has teeth. The
color in _Salmo clarkii_ is, as in other species, exceedingly variable.
In life there is always a deep-red blotch on the throat, between the
branches of the lower jaw and the membrane connecting them. This is not
found in other species, or is reduced to a narrow strip or pinkish
shade. It seems to be constant in all varieties of _Salmo clarkii_, at
all ages, thus furnishing a good distinctive character. It is the sign
manual of the Sioux Indians, and the anglers have already accepted from
this mark the name of cutthroat-trout. The cutthroat-trout of some
species is found in every suitable river and lake in the great basin of
Utah, in the streams of Colorado, Wyoming, and Montana, on both sides of
the Rocky Mountains. It is also found throughout Oregon, Washington,
Idaho, British Columbia, the coastwise islands of southeastern Alaska
(Baranof, etc.), to Kadiak and Bristol Bay, probably no stream or lake
suitable for trout-life being without it. In California the species
seems to be comparatively rare, and its range rarely extending south of
Cape Mendocino. Large sea-run individuals analogous to the steelheads
are sometimes found in the mouth of the Sacramento. In Washington and
Alaska this species regularly enters the sea. In Puget Sound it is a
common fish. These sea-run individuals are more silvery and less spotted
than those found in the mountain streams and lakes. The size of _Salmo
clarkii_ is subject to much variation. Ordinarily four to six pounds is
a large size; but in certain favored waters, as Lake Tahoe, and the
fjords of southeastern Alaska, specimens from twenty to thirty pounds
are occasionally taken.

Those species or individuals dwelling in lakes of considerable size,
where the water is of such temperature and depth as insures an ample
food-supply, will reach a large size, while those in a restricted
environment, where both the water and food are limited, will be small
directly in proportion to these environing restrictions. The trout of
the Klamath Lakes, for example, reach a weight of at least 17 pounds,
while in Fish Lake in Idaho mature trout do not exceed 8 to 9¼ inches in
total length or one-fourth pound in weight. In small creeks in the
Sawtooth Mountains and elsewhere they reach maturity at a length of 5 or
6 inches, and are often spoken of as brook-trout and with the impression
that they are a species different from the larger ones found in the
lakes and larger streams. But as all sorts and gradations between these
extreme forms may be found in the intervening and connecting waters, the
differences are not even of sub-specific significance.

[Illustration:

  FIG. 64.—Head of adult Trout-worm, _Dibothrium cordiceps_ Leidy, a
    parasite of _Salmo clarkii_. From intestine of white pelican,
    Yellowstone Lake. (After Linton.)
]

[Illustration:

  FIG. 65.—Median segments of _Dibothrium cordiceps_.
]

Dr. Evermann observes: "The various forms of cutthroat-trout vary
greatly in game qualities; even the same subspecies in different waters,
in different parts of its habitat, or at different seasons, will vary
greatly in this regard. In general, however, it is perhaps a fair
statement to say that the cutthroat-trout are regarded by anglers as
being inferior in gaminess to the Eastern brook-trout. But while this is
true, it must not by any means be inferred that it is without game
qualities, for it is really a fish which possesses those qualities in a
very high degree. Its vigor and voraciousness are determined largely, of
course, by the character of the stream or lake in which it lives. The
individuals which dwell in cold streams about cascades and seething
rapids will show marvelous strength and will make a fight which is
rarely equaled by its Eastern cousin; while in warmer and larger streams
and lakes they may be very sluggish and show but little fight. Yet this
is by no means always true. In the Klamath Lakes, where the trout grow
very large and where they are often very logy, one is occasionally
hooked which tries to the utmost the skill of the angler to prevent his
tackle from being smashed and at the same time save the fish."

Of the various forms derived from _Salmo clarkii_ some mere varieties,
some distinct species, the following are among the most marked:

_Salmo henshawi_, the trout of Lake Tahoe and its tributaries and
outlet, Truckee River, found in fact also in the Humboldt and the Carson
and throughout the basin of the former glacial lake called Lake
Lahontan. This is a distinct species from _Salmo clarkii_ and must be
regarded as the finest of all the cutthroat-trout. It is readily known
by its spotted belly, the black spots being evenly scattered over the
whole surface of the body, above and below. This is an excellent
game-fish, and from Lake Tahoe and Pyramid Lake it is brought in large
numbers to the markets of San Francisco. In the depths of Lake Tahoe,
which is the finest mountain lake of the Sierra Nevada, occurs a very
large variety which spawns in the lake, _Salmo henshawi tahoensis_. This
reaches a weight of twenty-eight pounds.

[Illustration:

  FIG. 66.—Tahoe Trout, _Salmo henshawi_ Gill & Jordan. Lake Tahoe,
    California.
]

In the Great Basin of Utah is found a fine trout, very close to the
ordinary cutthroat of the Columbia, from which it is derived. This is
known as _Salmo clarkii virginalis_. In Utah Lake it reaches a large
size.

In Waha Lake in Washington, a lake without outlet, is found a small
trout with peculiar markings called _Salmo clarkii bouvieri_.

In the head-waters of the Platte and Arkansas rivers is the small
green-back trout, green or brown, with red throat-patch and large black
spots. This is _Salmo clarkii stomias_, and it is especially fine in St.
Vrain's River and the streams of Estes Park. In Twin Lakes, a pair of
glacial lakes tributary of the Arkansas near Leadville, is found _Salmo
clarkii macdonaldi_, the yellow-finned trout, a large and very handsome
species living in deep water, and with the fins golden yellow. This
approaches the Colorado trout, _Salmo clarkii pleuriticus_, and it may
be derived from the latter, although it occurs in the same waters as the
very different green-back trout, or _Salmo clarkii stomias_.

[Illustration:

  FIG. 67.—Green-back Trout, _Salmo stomias_ Cope. Arkansas River,
    Leadville, Colo.
]

[Illustration:

  FIG. 68.—Yellow-fin Trout of Twin Lakes, _Salmo macdonaldi_ Jordan &
    Evermann. Twin Lakes, Colo.
]

Two fine trout derived from _Salmo clarkii_ have been lately discovered
by Dr. Daniel G. Elliot in Lake Southerland, a mountain lake near Lake
Crescent, but not connected with it, the two separated from the sea by
high waterfalls. These have been described by Dr. Seth E. Meek as _Salmo
jordani_, the "spotted trout" of Lake Southerland, and _Salmo
declivifrons_, the "salmon-trout." These seem to be distinct forms or
subspecies produced through isolation.

[Illustration:

  FIG. 69.—Rio Grande Trout, _Salmo clarkii spilurus_ Cope. Del Norte,
    Colo.
]

[Illustration:

  FIG. 70.—Colorado River Trout, _Salmo clarkii pleuriticus_ Cope.
    Trapper's Lake, Colo.
]

The Rio Grande trout (_Salmo clarkii spilurus_) is a large and profusely
spotted trout, found in the head-waters of the Rio Grande, the mountain
streams of the Great Basin of Utah, and as far south as the northern
part of Chihuahua. Its scales are still smaller than those of the
ordinary cutthroat-trout, and the black spots are chiefly confined to
the tail. Closely related to it is the trout of the Colorado Basin,
_Salmo clarkii pleuriticus_, a large and handsome trout with very small
scales, much sought by anglers in western Colorado, and abounding in all
suitable streams throughout the Colorado Basin.

=Hucho, the Huchen.=—The genus _Hucho_ has been framed for the Huchen or
Rothfisch (_Hucho hucho_) of the Danube, a very large trout, differing
from the genus _Salmo_ in having no teeth on the shaft of the vomer, and
from the _Salvelini_ at least in form and coloration. The huchen is a
long and slender, somewhat pike-like fish, with depressed snout and
strong teeth. The color is silvery, sprinkled with small black dots. It
reaches a size little inferior to that of the salmon, and it is said to
be an excellent food-fish. In northern Japan is a similar species,
_Hucho blackistoni_, locally known as Ito, a large and handsome trout
with very slender body, reaching a length of 2½ feet. It is well worthy
of introduction into American and European waters.

[Illustration:

  FIG. 71.—Ito, _Hucho blackistoni_ (Hilgendorf). Hokkaido, Japan.
]

=Salvelinus, the Charr.=—The genus _Salvelinus_ comprises the finest of
the _Salmonidæ_, from the point of view of the angler or the artist. In
England the species are known as charr or char, in contradistinction to
the black-spotted species of _Salmo_, which are called trout. The former
name has unfortunately been lost in America, where the name "trout" is
given indiscriminately to both groups, and, still worse, to numerous
other fishes (_Micropterus_, _Hexagrammos_, _Cynoscion_, _Agonostomus_)
wholly unlike the _Salmonidæ_ in all respects. It is sometimes said that
"the American brook-trout is no trout, nothing but a charr," almost as
though "charr" were a word of reproach. Nothing higher, however, can be
said of a salmonoid than that it is a "charr." The technical character
of the genus _Salvelinus_ lies in the form of its vomer. This is deeper
than in _Salmo_; and when the flesh is removed the bone is found to be
somewhat boat-shaped above, and with the shaft depressed and out of the
line of the head of the vomer. Only the head or chevron is armed with
teeth, and the shaft is covered by skin.

In color all the charrs differ from the salmon and trout. The body in
all is covered with round spots which are paler than the ground color,
and crimson or gray. The lower fins are usually edged with bright
colors. The sexual differences are not great. The scales, in general,
are smaller than in other _Salmonidæ_, and they are imbedded in the skin
to such a degree as to escape the notice of casual observers and even of
most anglers.

               "One trout scale in the scales I'd lay
               (If trout had scales), and 'twill outweigh
               The wrong side of the balances."—LOWELL.

The charrs inhabit, in general, only the clearest and coldest of
mountain streams and lakes, or bays of similar temperature. They are not
migratory, or only to a limited extent. In northern regions they descend
to the sea, where they grow much more rapidly and assume a nearly
uniform silvery-gray color. The different species are found in all
suitable waters throughout the northern parts of both continents, except
in the Rocky Mountains and Great Basin, where only the black-spotted
trout occur. The number of species of charr is very uncertain, as, both
in America and Europe, trivial variations and individual peculiarities
have been raised to the rank of species. More types, however, seem to be
represented in America than in Europe.

[Illustration:

  FIG. 72.—Rangeley Trout, _Salvelinus oquassa_ (Girard). Lake Oquassa,
    Maine.
]

The only really well-authenticated species of charr in European waters
is the red charr, sälbling, or ombre chevalier (_Salvelinus alpinus_).
This species is found in cold, clear streams in Switzerland, Germany,
and throughout Scandinavia and the British Islands. Compared with the
American charr or brook-trout, it is a slenderer fish, with smaller
mouth, longer fins, and smaller red spots, which are confined to the
sides of the body. It is a "gregarious and deep-swimming fish, shy of
taking the bait and feeding largely at night-time. It appears to require
very pure and mostly deep water for its residence." It is less tenacious
of life than the trout. It reaches a weight of from one to five pounds,
probably rarely exceeding the latter in size. The various charr
described from Siberia are far too little known to be enumerated here.

Of the American charr the one most resembling the European species is
the Rangeley Lake trout (_Salvelinus oquassa_). The exquisite little
fish is known in the United States only from the Rangeley chain of lakes
in western Maine. This is very close to the Greenland charr, _Salvelinus
stagnalis_, a beautiful species of the far north. The Rangeley trout is
much slenderer than the common brook-trout, with much smaller head and
smaller mouth. In life it is dark blue above, and the deep-red spots are
confined to the sides of the body. The species rarely exceeds the length
of a foot in the Rangeley Lakes, but in some other waters it reaches a
much larger size. So far as is known it keeps itself in the depths of
the lake until its spawning season approaches, in October, when it
ascends the stream to spawn.

[Illustration:

  FIG. 73.—Sunapee Trout, _Salvelinus aureolus_ Bean. Sunapee Lake, N.
    H.
]

Still other species of this type are the Sunapee trout, _Salvelinus
aureolus_, a beautiful charr almost identical with the European species,
found in numerous ponds and lakes of eastern New Hampshire and
neighboring parts of Maine. Mr. Garman regards this trout as the
offspring of an importation of the ombre chevalier and not as a native
species, and in this view he may be correct. _Salvelinus alipes_ of the
far north may be the same species. Another remarkable form is the Lac de
Marbre trout of Canada, _Salvelinus marstoni_ of Garman.

In Arctic regions another species, called _Salvelinus naresi_, is very
close to _Salvelinus oquassa_ and may be the same.

Another beautiful little charr, allied to _Salvelinus stagnalis_, is the
Floeberg charr (_Salvelinus arcturus_). This species has been brought
from Victoria Lake and Floeberg Beach, in the extreme northern part of
Arctic America, the northernmost point whence any salmonoid has been
obtained.

[Illustration:

  FIG. 74.—Speckled Trout (male), _Salvelinus fontinalis_ (Mitchill).
    New York.
]

[Illustration:

  FIG. 75.—Brook Trout, _Salvelinus fontinalis_ (Mitchill), natural
    size. (From life by Dr. R. W. Shufeldt.)
]

The American charr, or, as it is usually called, the brook-trout
(_Salvelinus fontinalis_), although one of the most beautiful of fishes,
is perhaps the least graceful of all the genuine charrs. It is
technically distinguished by the somewhat heavy head and large mouth,
the maxillary bone reaching more or less beyond the eye. There are no
teeth on the hyoid bone, traces at least of such teeth being found in
nearly all other species. Its color is somewhat different from that of
the others, the red spots being large and the black more or less mottled
and barred with darker olive. The dorsal and caudal fins are likewise
barred or mottled, while in the other species they are generally uniform
in color. The brook-trout is found only in streams east of the
Mississippi and Saskatchewan. It occurs in all suitable streams of the
Alleghany region and the Great Lake system, from the Chattahoochee River
in northern Georgia northward at least to Labrador and Hudson Bay, the
northern limits of its range being as yet not well ascertained. It
varies greatly in size, according to its surroundings, those found in
lakes being larger than those resident in small brooks. Those found
farthest south, in the head-waters of the Chattahoochee, Savannah,
Catawba, and French Broad, rarely pass the dimensions of fingerlings.
The largest specimens are recorded from the sea along the Canadian
coast. These frequently reach a weight of ten pounds; and from their
marine and migratory habits, they have been regarded as forming a
distinct variety (_Salvelinus fontinalis immaculatus_), but this form is
merely a sea-run brook-trout. The largest fresh-water specimens rarely
exceed seven pounds in weight. Some unusually large brook-trout have
been taken in the Rangeley Lakes, the largest known to me having a
reputed weight of eleven pounds. The brook-trout is the favorite
game-fish of American waters, preëminent in wariness, in beauty, and in
delicacy of flesh. It inhabits all clear and cold waters within its
range, the large lakes and the smallest ponds, the tiniest brooks and
the largest rivers; and when it can do so without soiling its
aristocratic gills on the way, it descends to the sea and grows large
and fat on the animals of the ocean. Although a bold biter it is a wary
fish, and it often requires much skill to capture it. It can be caught,
too, with artificial or natural flies, minnows, crickets, worms,
grasshoppers, grubs, the spawn of other fish, or even the eyes or cut
pieces of other trout. It spawns in the fall, from September to late in
November. It begins to reproduce at the age of two years, then having a
length of about six inches. In spring-time the trout delight in rapids
and swiftly running water; and in the hot months of midsummer they
resort to deep, cool, and shaded pools. Later, at the approach of the
spawning season, they gather around the mouths of cool, gravelly brooks,
whither they resort to make their beds.[10]

Footnote 10:

  Hallock.

The trout are rapidly disappearing from our streams through the agency
of the manufacturer and the summer boarder. In the words of an excellent
angler, the late Myron W. Reed of Denver: "This is the last generation
of trout-fishers. The children will not be able to find any. Already
there are well-trodden paths by every stream in Maine, in New York, and
in Michigan. I know of but one river in North America by the side of
which you will find no paper collar or other evidence of civilization.
It is the Nameless River. Not that trout will cease to be. They will be
hatched by machinery and raised in ponds, and fattened on chopped liver,
and grow flabby and lose their spots. The trout of the restaurant will
not cease to be. He is no more like the trout of the wild river than the
fat and songless reedbird is like the bobolink. Gross feeding and easy
pond-life enervate and deprave him. The trout that the children will
know only by legend is the gold-sprinkled, living arrow of the white
water; able to zigzag up the cataract; able to loiter in the rapids;
whose dainty meat is the glancing butterfly."

The brook-trout adapts itself readily to cultivation in artificial
ponds. It has been successfully transported to Europe, and it is already
abundant in certain streams in England, in California, and elsewhere.

In Dublin Pond, New Hampshire, is a gray variety without red spots,
called _Salvelinus agassizi_.

[Illustration:

  FIG. 76.—Malma Trout, or "Dolly Varden," _Salvelinus malma_ (Walbaum).
    Cook Inlet, Alaska.
]

The "Dolly Varden" trout, or malma (_Salvelinus malma_), is very similar
to the brook-trout, closely resembling it in size, form, color, and
habits. It is found always to the westward of the Rocky Mountains, in
the streams of northern California, Oregon, Washington, and British
Columbia, Alaska, and Kamchatka, as far as the Kurile Islands. It
abounds in the sea in the northward, and specimens of ten to twelve
pounds weight are not uncommon in Puget Sound and especially in Alaska.
The Dolly Varden trout is, in general, slenderer and less compressed
than the Eastern brook-trout. The red spots are found on the back of the
fish as well as on the sides, and the back and upper fins are without
the blackish marblings and blotches seen in _Salvelinus fontinalis_. In
value as food, in beauty, and in gaminess _Salvelinus malma_ is very
similar to its Eastern cousin.

[Illustration:

  FIG. 77.—The Dolly Varden Trout, _Salvelinus malma_ (Walbaum). Lake
    Pend d'Oreille, Idaho. (After Evermann.)
]

In Alaska the Dolly Varden, locally known as salmon-trout, is very
destructive to the eggs of the salmon, and countless numbers are taken
in the salmon-nets of Alaska and thrown away as useless by the canners.
In every coastwise stream of Alaska the water fairly "boils" with these
trout. They are, however, not found in the Yukon. In northern Japan
occurs _Salvelinus pluvius_, the iwana, a species very similar to the
Dolly Varden, but not so large or so brightly colored. In the Kurile
region and Kamchatka is another large charr, _Salvelinus kundscha_, with
the spots large and cream-color instead of crimson.

[Illustration:

  FIG. 78.—Great Lake Trout, _Cristivomer namaycush_ (Walbaum). Lake
    Michigan.
]

=Cristivomer, the Great Lake Trout.=—Allied to the true charrs, but now
placed by us in a different genus, _Cristivomer_, is the Great Lake
trout, otherwise known as Mackinaw trout, longe, or togue (_Cristivomer
namaycush_). Technically this fish differs from the true charrs in
having on its vomer a raised crest behind the chevron and free from the
shaft. This crest is armed with strong teeth. There are also large
hooked teeth on the hyoid bone, and the teeth generally are
proportionately stronger than in most of the other species. The Great
Lake trout is grayish in color, light or dark according to its
surroundings; and the body is covered with round paler spots, which are
gray instead of red. The dorsal and caudal fins are marked with darker
reticulations, somewhat as in the brook-trout. This noble species is
found in all the larger lakes from New England and New York to
Wisconsin, Montana, the Mackenzie River, and in all the lakes tributary
to the Yukon in Alaska. We have taken examples from Lake Bennett, Lake
Tagish, Summit Lake (White Pass), and have seen specimens from Lake La
Hache in British Columbia. It reaches a much larger size than any
_Salvelinus_, specimens of from fifteen to twenty pounds weight being
not uncommon, while it occasionally attains a weight of fifty to eighty
pounds. As a food-fish it ranks high, although it may be regarded as
somewhat inferior to the brook-trout or the whitefish. Compared with
other salmonoids, the Great Lake trout is a sluggish, heavy, and
ravenous fish. It has been known to eat raw potato, liver, and
corn-cobs,—refuse thrown from passing steamers. According to Herbert, "a
coarse, heavy, stiff rod, and a powerful oiled hempen or flaxen line, on
a winch, with a heavy sinker; a cod-hook, baited with any kind of flesh,
fish, or fowl,—is the most successful, if not the most orthodox or
scientific, mode of capturing him. His great size and immense strength
alone give him value as a fish of game; but when hooked he pulls
strongly and fights hard, though he is a boring, deep fighter, and
seldom if ever leaps out of the water, like the true salmon or
brook-trout."

In the depths of Lake Superior is a variety of the Great Lake trout
known as the Siscowet (_Cristivomer namaycush siskawitz_), remarkable
for its extraordinary fatness of flesh. The cause of this difference
lies probably in some peculiarity of food as yet unascertained.

=The Ayu, or Sweetfish.=—The ayu, or sweetfish, of Japan, _Plecoglossus
altivelis_, resembles a small trout in form, habits, and scaling. Its
teeth are, however, totally different, being arranged on serrated plates
on the sides of the jaws, and the tongue marked with similar folds. The
ayu abounds in all clear streams of Japan and Formosa. It runs up from
the sea like a salmon. It reaches the length of about a foot. The flesh
is very fine and delicate, scarcely surpassed by that of any other fish
whatsoever. It should be introduced into clear short streams throughout
the temperate zones.

[Illustration:

  FIG. 79.—Ayu, or Japanese Samlet, _Plecoglossus altivelis_ Schlegel.
    Tamagawa, Tokyo, Japan.
]

In the river at Gifu in Japan and in some other streams the ayu is
fished for on a large scale by means of tamed cormorants. This is
usually done from boats in the night by the light of torches.

=Cormorant-fishing.=—The following account of cormorant-fishing is
taken, by the kind permission of Mr. Caspar W. Whitney, from an article
contributed by the writer to _Outing_, April, 1902:

Tamagawa means Jewel River, and no water could be clearer. It rises
somewhere up in the delectable mountains to the eastward of Musashi,
among the mysterious pines and green-brown fir-trees, and it flows
across the plains bordered by rice-fields and mulberry orchards to the
misty bay of Tokyo. It is, therefore, a river of Japan, and along its
shores are quaint old temples, each guarding its section of primitive
forest, picturesque bridges, huddling villages, and torii, or gates
through which the gods may pass.

The stream itself is none too large—a boy may wade it—but it runs on a
wide bed, which it will need in flood-time, when the snow melts in the
mountains. And this broad flood-bed is filled with gravel, with
straggling willows, showy day-lilies, orange amaryllis, and the little
sky-blue spider-flower, which the Japanese call chocho, or
butterfly-weed.

In the Tamagawa are many fishes: shining minnows in the white ripples,
dark catfishes in the pools and eddies, and little sculpins and gobies
lurking under the stones. Trout dart through its upper waters, and at
times salmon run up from the sea.

But the one fish of all its fishes is the ayu. This is a sort of dwarf
salmon, running in the spring and spawning in the rivers just as a
salmon does. But it is smaller than any salmon, not larger than a smelt,
and its flesh is white and tender, and so very delicate in its taste and
odor that one who tastes it crisply fried or broiled feels that he has
never tasted real fish before. In all its anatomy the ayu is a salmon, a
dwarf of its kind, one which our ancestors in England would have called
a "samlet." Its scientific name is _Plecoglossus altivelis_.
_Plecoglossus_ means plaited tongue, and _altivelis_, having a high
sail; for the skin of the tongue is plaited or folded in a curious way,
and the dorsal fin is higher than that of the salmon, and one poetically
inclined might, if he likes, call it a sail. The teeth of the ayu are
very peculiar, for they constitute a series of saw-edged folds or plaits
along the sides of the jaws, quite different from those of any other
fish whatsoever.

In size the ayu is not more than a foot to fifteen inches long. It is
like a trout in build, and its scales are just as small. It is light
yellowish or olive in color, growing silvery below. Behind its gills is
a bar of bright shining yellow, and its adipose fin is edged with
scarlet. The fins are yellow, and the dorsal fin shaded with black,
while the anal fin is dashed with pale red.

So much for the river and the ayu. It is time for us to go afishing. It
is easy enough to find the place, for it is not more than ten miles out
of Tokyo, on a fine old farm just by the ancient Temple of Tachikawa,
with its famous inscribed stone, given by the emperor of China.

At the farmhouse, commodious and hospitable, likewise clean and charming
after the fashion of Japan, we send for the boy who brings our
fishing-tackle.

They come waddling into the yard, the three birds with which we are to
do our fishing. Black cormorants they are, each with a white spot behind
its eye, and a hoarse voice, come of standing in the water, with which
it says _y-eugh_ whenever a stranger makes a friendly overture. The
cormorants answer to the name of Ou, which in Japanese is something like
the only word the cormorants can say. The boy puts them in a box
together and we set off across the drifted gravel to the Tamagawa.
Arrived at the stream, the boy takes the three cormorants out of the box
and adjusts their fishing-harness. This consists of a tight ring about
the bottom of the neck, of a loop under each wing, and a directing line.

Two other boys take a low net. They drag it down the stream, driving the
little fishes—ayu, zakko, haë, and all the rest—before it. The boy with
the cormorants goes in advance. The three birds are eager as pointer
dogs, and apparently full of perfect enjoyment. To the right and left
they plunge with lightning strokes, each dip bringing up a shining fish.
When the bird's neck is full of fishes down to the level of the
shoulders, the boy draws him in, grabs him by the leg, and shakes him
unceremoniously over a basket until all the fishes have flopped out.

The cormorants watch the sorting of the fish with eager eyes and much
repeating of _y-eugh_, the only word they know. The ayu are not for
them, and some of the kajikas and hazés were prizes of science. But
zakko (the dace) and haë (the minnow) were made for the cormorant. The
boy picks out the chubs and minnows and throws them to one bird and then
another. Each catches his share on the fly, swallows it at one gulp, for
the ring is off his neck by this time, and then says _y-eugh_, which
means that he likes the fun, and when we are ready will be glad to try
again. And no doubt they have tried it many times since, for there are
plenty of fishes in the Jewel River, zakko and haë as well as ayu.

=Fossil Salmonidæ.=—Fossil salmonidæ are rare and known chiefly from
detached scales, the bones in this family being very brittle and easily
destroyed. Nothing is added to our knowledge of the origin of these
fishes from such fossils.

A large fossil trout or salmon, called _Rhabdofario lacustris_, has been
brought from the Pliocene at Catherine's Creek, Idaho. It is known from
the skull only. _Thaumaturus luxatus_, from the Miocene of Bohemia,
shows the print of the adipose fin. As already stated (p. 62), fragments
of the hooked jaws of salmon, from pleistocene deposits in Idaho, are in
the museum of the University of California.



                               CHAPTER VI
                       THE GRAYLING AND THE SMELT


=THE Grayling, or Thymallidæ.=—The small family of _Thymallidæ_, or
grayling, is composed of finely organized fishes allied to the trout,
but differing in having the frontal bones meeting on the middle line of
the skull, thus excluding the frontals from contact with the
supraoccipital. The anterior half of the very high dorsal is made up of
unbranched simple rays. There is but one genus, _Thymallus_, comprising
very noble game-fishes characteristic of subarctic streams.

[Illustration:

  FIG. 80.—Alaska Grayling, _Thymallus signifer_ Richardson. Nulato,
    Alaska.
]

The grayling, _Thymallus_, of Europe, is termed by Saint Ambrose "the
flower of fishes." The teeth on the tongue, found in all the trout and
salmon, are obsolete in the grayling. The chief distinctive peculiarity
of the genus _Thymallus_ is the great development of the dorsal fin,
which has more rays (20 to 24) than are found in any of the _Salmonidæ_,
and the fin is also higher. All the species are gaily colored, the
dorsal fin especially being marked with purplish or greenish bands and
bright rose-colored spots; while the body is mostly purplish gray, often
with spots of black. Most of the species rarely exceed a foot in length,
but northward they grow larger. Grayling weighing five pounds have been
taken in England; and according to Dr. Day they are said in Lapland to
reach a weight of eight or nine pounds. The grayling in all countries
frequent clear, cold brooks, and rarely, if ever, enter the sea, or even
the larger lakes. They congregate in small shoals in the streams, and
prefer those which have a succession of pools and shallows, with a sandy
or gravelly rather than rocky bottom. The grayling spawns on the
shallows in April or May (in England). It is non-migratory in its
habits, depositing its ova in the neighborhood of its usual haunts. The
ova are far more delicate and easily killed than those of the trout or
charr. The grayling and the trout often inhabit the same waters, but not
altogether in harmony. It is said that the grayling devours the eggs of
the trout. It is certain that the trout feed on the young grayling. As a
food-fish, the grayling of course ranks high; and it is beloved by the
sportsman. They are considered gamy fishes, although less strong than
the brook-trout, and perhaps less wary. The five or six known species of
grayling are very closely related, and are doubtless comparatively
recent offshoots from a common stock, which has now spread itself widely
through the northern regions.

The common grayling of Europe (_Thymallus thymallus_) is found
throughout northern Europe, and as far south as the mountains of Hungary
and northern Italy. The name _Thymallus_ was given by the ancients,
because the fish, when fresh, was said to have the odor of water-thyme.
Grayling belonging to this or other species are found in the waters of
Russia and Siberia.

The American grayling (_Thymallus signifer_) is widely distributed in
British America and Alaska. In the Yukon it is very abundant, rising
readily to the fly. In several streams in northern Michigan, Au Sable
River, and Jordan River in the southern peninsula, and Otter Creek near
Keweenaw in the northern peninsula, occurs a dwarfish variety or species
with shorter and lower dorsal fins, known to anglers as the Michigan
grayling (_Thymallus tricolor_). This form has a longer head, rather
smaller scales, and the dorsal fin rather lower than in the northern
form (_signifer_); but the constancy of these characters in specimens
from intermediate localities is yet to be proved. Another very similar
form, called _Thymallus montanus_, occurs in the Gallatin, Madison, and
other rivers of Western Montana tributary to the Missouri. It is locally
still abundant and one of the finest of game-fishes. It is probable that
the grayling once had a wider range to the southward than now, and that
so far as the waters of the United States are concerned it is tending
toward extinction. This tendency is, of course, being accelerated in
Michigan by lumbermen and anglers. The colonies of grayling in Michigan
and Montana are probably remains of a post-glacial fauna.

[Illustration:

  FIG. 81.—Michigan Grayling, _Thymallus tricolor_ Cope. Au Sable River,
    Mich.
]

=The Argentinidæ.=—The family of _Argentinidæ_, or smelt, is very
closely related to the _Salmonidæ_, representing a dwarf series of
similar type. The chief essential difference lies in the form of the
stomach, which is a blind sac, the two openings near together, and about
the second or pyloric opening there are few if any pyloric cæca. In all
the _Salmonidæ_ the stomach has the form of a siphon, and about the
pylorus there are very many pyloric cæca. The smelt have the adipose fin
and the general structure of the salmon. All the species are small in
size, and most of them are strictly marine, though some of them ascend
the rivers to spawn, just as salmon do, but not going very far. A few
kinds become landlocked in ponds. Most of the species are confined to
the north temperate zone, and a few sink into the deep seas. All that
are sufficiently abundant furnish excellent food, the flesh being
extremely delicate and often charged with a fragrant oil easy of
digestion.

[Illustration:

  FIG. 82.—Smelt, _Osmerus mordux_ (Mitchill). Wood's Hole, Mass.
]

The best-known genus, _Osmerus_, includes the smelt, or spirling
(éperlan), of Europe, and its relatives, all excellent food-fishes,
although quickly spoiling in warm weather. _Osmerus eperlanus_ is the
European species; _Osmerus mordax_ of our eastern coast is very much
like it, as is also the rainbow-smelt, _Osmerus dentex_ of Japan and
Alaska. A larger smelt, _Osmerus albatrossis_, occurs on the coast of
Alaska, and a small and feeble one, _Osmerus thaleichthys_, mixed with
other small or delicate fishes, is the whitebait of the San Francisco
restaurants. The whitebait of the London epicure is made up of the young
of herrings and sprats of different species. The still more delicate
whitebait of the Hong Kong hotels is the icefish, _Salanx chinensis_.
_Retropinna retropinna_, so called from the backward insertion of its
dorsal, is the excellent smelt of the rivers of New Zealand. All the
other species belong to northern waters. _Mesopus_, the surf-smelt, has
a smaller mouth than _Osmerus_ and inhabits the North Pacific. The
California species, _Mesopus pretiosus_, of Neah Bay has, according to
James G. Swan, "the belly covered with a coating of yellow fat which
imparts an oily appearance to the water where the fish has been cleansed
or washed and makes them the very perfection of pan-fish." This species
spawns in late summer along the surf-line. According to Mr. Swan the
water seems to be filled with them. "They come in with the flood-tide,
and when a wave breaks upon the beach they crowd up into the very foam,
and as the surf recedes many will be seen flapping on the sand and
shingle, but invariably returning with the undertow to deeper water."
The Quilliute Indians of Washington believe that "the first surf-smelts
that appear must not be sold or given away to be taken to another place,
nor must they be cut transversely, but split open with a mussel-shell."

The surf-smelt is marine, as is also a similar species, _Mesopus
japonicus_, in Japan. _Mesopus olidus_, the pond-smelt of Alaska,
Kamchatka, and Northern Japan, spawns in fresh-water ponds.

[Illustration:

  FIG. 83.—Eulachon, or Ulchen. _Thaleichthys pretiosus_ Girard.
    Columbia River. Family _Argentinidæ_.
]

Still more excellent as a food-fish than even these exquisite species is
the famous eulachon, or candle-fish (_Thaleichthys pacificus_). The
Chinook name, usually written eulachon, is perhaps more accurately
represented as ulchen. This little fish has the form of a smelt and
reaches the length of nearly a foot. In the spring it ascends in
enormous numbers all the rivers north of the Columbia, as far as
Skaguay, for a short distance for the purpose of spawning. These runs
take place usually in advance of the salmon-runs. Various predatory
fishes and sea-birds persecute the eulachon during its runs, and even
the stomachs of the sturgeons are often found full of the little fishes,
which they have taken in by their sucker-like mouths. At the time of the
runs the eulachon are extremely fat, so much so that it is said that
when dried and a wick drawn through the body they may be used as
candles. On Nass River, in British Columbia, a stream in which their run
is greatest, there is a factory for the manufacture of eulachon-oil from
them. This delicate oil is proposed as a substitute for cod-liver oil in
medicine. Whatever may be its merits in this regard, it has the
disadvantage in respect to salability of being semi-solid or lard-like
at ordinary temperatures, requiring melting to make it flow as oil. The
eulachon is a favorite pan-fish in British Columbia. The writer has had
considerable experience with it, broiled and fried, in its native
region, and has no hesitation in declaring it to be the best-flavored
food-fish in American waters. It is fat, tender, juicy, and richly
flavored, with comparatively few troublesome bones. It does not,
however, bear transportation well. The Indians in Alaska bury the
eulachon in the ground in great masses. After the fish are well decayed
they are taken out and the oil pressed from them. The odor of the fish
and the oil is then very offensive, less so, however, than that of some
forms of cheese eaten by civilized people.

[Illustration:

  FIG. 84.—Page of William Clark's handwriting with sketch of the
    Eulachon (_Thaleichthys pacificus_), the first notice of the
    species. Columbia River, 1805. (Expedition of Lewis & Clark.)
    (Reproduced from the original in the possession of his granddaughter
    Mrs. Julia Clark Voorhis, through the courtesy of Messrs. Dodd, Mead
    & Company, publishers of the "Original Journals of the Lewis and
    Clark Expedition.")
]

The capelin (_Mallotus villosus_) closely resembles the eulachon,
differing mainly in its broader pectorals and in the peculiar scales of
the males. In the male fish a band of scales above the lateral line and
along each side of the belly become elongate, closely imbricated, with
the free points projecting, giving the body a villous appearance. It is
very abundant on the coasts of Arctic America, both in the Atlantic and
the Pacific, and is an important source of food for the natives of those
regions.

[Illustration:

  FIG. 85.—Capelin, _Mallotus villosus_ L. Crosswater Bay.
]

This species spawns in the surf, and the writer has seen them in August
cast on the shores of the Alaskan islands (as at Metlakahtla in 1897),
living and dead, in numbers which seem incredible. The males are then
distorted, and it seems likely that all of them perish after spawning.
The young are abundant in all the northern fiords. Even more inordinate
numbers are reported from the shores of Greenland.

The capelin seems to be inferior to the eulachon as a food-fish, but to
the natives of arctic regions in both hemispheres it is a very important
article of food. Fossil capelin are found in abundance in recent shales
in Greenland enveloped in nodules of clay. In the open waters about the
Aleutian Islands a small smelt, _Therobromus callorhini_, occurs in very
great abundance and forms the chief part of the summer food of the
fur-seal. Strangely enough, no complete specimen of this fish has yet
been seen by man, although thousands of fragments have been taken from
seals' stomachs. From these fragments Mr. Frederick A. Lucas has
reconstructed the fish, which must be an ally of the surf-smelt,
probably spawning in the open ocean of the north.

The silvery species called _Argentina_ live in deeper water and have no
commercial importance. _Argentina silus_, with prickly scales, occurs in
the North Sea. Several fossils have been doubtfully referred to
_Osmerus_.

=The Microstomidæ.=—The small family of _Microstomidæ_ consists of a few
degraded smelt, slender in form, with feeble mouth and but three or four
branchiostegals, rarely taken in the deep seas. _Nansenia grœnlandica_
was found by Reinhardt off the coast of Greenland, and six or eight
other species of _Microstoma_ and _Bathylagus_ have been brought in by
the deep-sea explorations.

=The Salangidæ, or Icefishes.=—Still more feeble and insignificant are
the species of _Salangidæ_, icefishes, or Chinese whitebait, which may
be described as _Salmonidæ_ reduced to the lowest terms. The body is
long and slender, perfectly translucent, almost naked, and with the
skeleton scarcely ossified. The fins are like those of the salmon, the
head is depressed, the jaws long and broad, somewhat like the bill of a
duck, and within there are a few disproportionately strong canine teeth,
those of the lower jaw somewhat piercing the upper. The alimentary canal
is straight for its whole length, without pyloric cæca. These little
fishes, two to five inches long, live in the sea in enormous numbers and
ascend the rivers of eastern Asia for the purpose of spawning. It is
thought by some that they are annual fishes, all dying in the fall after
reproduction, the species living through the winter only within its
eggs. But this is only suspected, not proved, and the species will repay
the careful study which some of the excellent naturalists of Japan are
sure before long to give to it. The species of _Salanx_ are known as
whitebait, in Japan as _Shiro-uwo_, which means exactly the same thing.
They are also sometimes called icefish (_Hingio_), which, being used for
no other fish, may be adopted as a group name for _Salanx_.

The species are _Salanx chinensis_ from Canton, _Salanx hyalo cranius_
from Korea and northern China, _Salanx microdon_ from northern Japan,
and _Salanx ariakensis_ from the southern island of Kiusiu. The Japanese
fishes are species still smaller and feebler than their relatives from
the mainland.

=The Haplochitonidæ.=—The _Haplochitonidæ_ are trout-like fishes of the
south temperate zone, differing from the _Salmonidæ_ mainly in the
extension of the premaxillary until, as in the perch-like fishes, it
forms the outer border of the upper jaw. The adipose fin is present as
in all the salmon and smelt. _Haplochiton_ of Tierra del Fuego and the
Falkland Islands is naked, while in _Prototroctes_ of Australia and New
Zealand the body, as in all salmon, trout, and smelt, is covered with
scales. _Prototroctes maræna_ is the yarra herring of Australia. The
closely related family of _Galaxiidæ_, also Australian, but lacking the
adipose fin, is mentioned in a later chapter.

[Illustration:

  FIG. 86.—Icefish, _Salanx hyalocranius_ Abbott. Family _Salangidæ_.
    Tientsin, China.
]

=Stomiatidæ.=—The _Stomiatidæ_, with elongate bodies, have the mouth
enormous, with fang-like teeth, usually barbed. Of the several species
_Stomias ferox_ is best known. According to Dr. Boulenger, these fishes
are true _Isospondyli_.

[Illustration:

  FIG. 87.—_Stomias ferox_ Reinhardt. Banquereau.
]

_Astronesthidæ_ is another small group of small fishes naked and black,
with long canines, found in the deep sea.

The _Malacosteidæ_ is a related group with extremely distensible mouth,
the species capable of swallowing fishes much larger than themselves.

The viper-fishes (_Chauliodontidæ_) are very feeble and very voracious
little fishes occasionally brought up from the depths. _Chauliodus
sloanei_ is notable for the length of the fangs.

Much smaller and feebler are the species of the closely related family
of _Gonostomidæ_. _Gonostoma_ and _Cyclothone_ dwell in oceanic abysses.
One species, _Cyclothone elongata_, occurs at the depth of from half a
mile to nearly four miles almost everywhere throughout the oceans. It is
probably the most widely distributed, as well as one of the feeblest and
most fragile, of all bassalian or deep-sea fishes.

[Illustration:

  FIG. 88.—_Chauliodus sloanei_ Schneider. Grand Banks.
]

=Suborder Iniomi, the Lantern-fishes.=—The suborder _Iniomi_ (ἰνίον,
nape; ὤμος, shoulder) comprises soft-rayed fishes, in which the
shoulder-girdle has more or less lost its completeness of structure as
part of the degradation consequent on life in the abysses of the sea.
These features distinguish these forms from the true _Isospondyli_, but
only in a very few of the species have these characters been verified by
actual examination of the skeleton. The mesocoracoid arch is wanting or
atrophied in all of the species examined, and the orbitosphenoid is
lacking, so far as known. The group thus agrees in most technical
characters with the _Haplomi_, in which group they are placed by Dr.
Boulenger. On the other hand the relationships to the _Isospondyli_ are
very close, and the _Iniomi_ have many traits suggesting degenerate
_Isospondyli_. The post-temporal has lost its usual hold on the skull
and may touch the occiput on the sides of the cranium. Nearly all the
species are soft in body, black or silvery over black in color, and all
that live in the deep sea are provided with luminous spots or glands
giving light in the abysmal depths. These spots are wanting in the few
shore species, as also in those which approach most nearly to the
_Salmonidæ_, these being presumably the most primitive of the group. In
these also the post-temporal touches the back of the cranium near the
side. In the majority of the _Iniomi_ the adipose fin of the _Salmonidæ_
is retained. From the phosphorescent spots is derived the general name
of lantern-fishes applied of late years to many of the species. Most of
these are of recent discovery, results of the remarkable work in
deep-sea dredging begun by the _Albatross_ and the _Challenger_. All of
the species are carnivorous, and some, in spite of their feeble muscles,
are exceedingly voracious, the mouth being armed with veritable daggers
and spears.

=Aulopidæ.=—Most primitive of the _Iniomi_ is the family of _Aulopidæ_,
having an adipose fin, a normal maxillary, and no luminous spots. The
rough firm scales suggest those of the berycoid fishes. The few species
of _Aulopus_ and _Chlorophthalmus_ are found in moderate depths.
_Aulopus purpurissatus_ is the "Sergeant Baker" of the Australian
fishermen.

[Illustration:

  FIG. 89.—Lizard-fish, _Synodus fætens_ L. Charleston, S. C.
]

=The Lizard-fishes.=—The _Synodontidæ_, or lizard-fishes, have
lizard-like heads with very large mouth. The head is scaly, a character
rare among the soft-rayed fishes. The slender maxillary is grown fast to
the premaxillary, and the color is not black. Most of the species are
shore-fishes and some are brightly colored. _Synodus fætens_ is the
common lizard-fish, or galliwasp, of our Atlantic coast. _Synodus
varius_ of the Pacific is brightly colored, olive-green and orange-red
types of coloration existing at different depths. Most of the species
lie close to the bottom and are mottled gray like coral sand. A few
occur in oceanic depths. The "Bombay duck" of the fishermen of India is
a species of _Harpodon_, _H. nehereus_, with large mouth and
arrow-shaped teeth. The dried fish is used as a relish.

The _Benthosauridæ_ are deep-sea fishes of similar type, but with
distinct maxillaries. The _Bathypteroidæ_, of the deep seas, resemble
_Aulopus_, but have the upper and lower pectoral rays filiform,
developed as organs of touch in the depths in which the small eyes
become practically useless.

=Ipnopidæ.=—In the _Ipnopidæ_ the head is depressed above and the two
eyes are flattened and widened so as to occupy most of its upper
surface. These structures were at first supposed to be luminous organs,
but Professor Moseley has shown them to be eyes. "They show a flattened
cornea extending along the median line of the snout, with a large retina
composed of peculiar rods which form a complicated apparatus destined
undoubtedly to produce an image and to receive especial luminous rays."
The single species, _Ipnops murrayi_, is black in color and found at the
depth of 2½ miles in various seas.

[Illustration:

  FIG. 90.—_Ipnops murrayi_ Günther.
]

The existence of well-developed eyes among fishes destined to live in
the dark abysses of the ocean seems at first contradictory, but we must
remember that these singular forms are descendants of immigrants from
the shore and from the surface. "In some cases the eyes have not been
specially modified, but in others there have been modifications of a
luminous mucous membrane leading on the one hand to phosphorescent
organs more or less specialized, or on the other to such remarkable
structures as the eyes of _Ipnops_, intermediate between true eyes and
phosphorescent plates. In fishes which cannot see, and which retain for
their guidance only the general sensibility of the integuments and the
lateral line, these parts soon acquire a very great delicacy. The same
is the case with tactile organs (as in _Bathypterois_ and
_Benthosaurus_), and experiments show that barbels may become organs of
touch adapted to aquatic life, sensitive to the faintest movements or
the slightest displacement, with power to give the blinded fishes full
cognizance of the medium in which they live."

=Rondeletiidæ.=—The _Rondeletiidæ_ are naked black fishes with small
eyes, without adipose fin and without luminous spots, taken at great
depths in the Atlantic. The relationship of these fishes is wholly
uncertain.

[Illustration:

  FIG. 91.—_Cetomimus gillii_ Goode & Bean. Gulf Stream.
]

The _Cetomimidæ_ are near allies of the _Rondeletiidæ_, having the mouth
excessively large, with the peculiar form seen in the right whales,
which these little fishes curiously resemble.

[Illustration:

  FIG. 92.—Headlight Fish, _Diaphus lucidus_ Goode & Bean. Gulf Stream.
]

=Myctophidæ.=—The large family of _Myctophidæ_, or lantern-fishes, is
made up of small fishes allied to the _Aulopidæ_, but with the body
covered with luminous dots, highly specialized and symmetrically
arranged. Most of them belong to the deep sea, but others come to the
surface in the night or during storms when the sunlight is absent.
Through this habit they are often thrown by the waves on the decks of
small vessels. Largely from Danish merchant-vessels, Dr. Lütken has
obtained the unrivaled collection of these sea-waifs preserved in the
Museum of the University of Copenhagen. The species are all small in
size and feeble in structure, the prey of the larger fishes of the
depths, from which their lantern-like spots and large eyes help them to
escape. The numerous species are now ranged in about fifteen genera,
although earlier writers placed them all in a single genus _Myctophum_
(_Scopelus_).

[Illustration:

  FIG. 93.—Lantern-fish, _Myctophum opalinum_ Goode & Bean. Gulf Stream.
]

In the genus _Diaphus_ (_Æthoprora_) there is a large luminous gland on
the end of the short snout, like the headlight of an engine. In
_Dasyscopelus_ the scales are spinescent, but in most of the genera, as
in _Myctophum_, the scales are cycloid and caducous, falling at the
touch. In _Diaphus_ the luminous spots are crossed by a septum giving
them the form of the Greek letter θ (theta). One of the commonest
species is _Myctophum humboldti_.

[Illustration:

  FIG. 94.—Lantern-fish, _Ceratoscopelus madeirensis_ (Lowe). Gulf
    Stream.
]

=Chirothricidæ.=—The remarkable extinct family of _Chirothricidæ_ may be
related to the _Synodontidæ_, or _Myctophidæ_. In this group the teeth
are feeble, the paired fins much enlarged, and the ventrals are well
forward. The dorsal fin, inserted well forward, has stout basal bones.
_Chirothrix libanicus_ of the Cretaceous of Mt. Lebanon is remarkable
for its excessively large ventral fins. _Telepholis_ is a related genus.
_Exocœtoides_ with rounded caudal fin is probably the type of a distinct
family, _Exocœtoididæ_, the caudal fin being strongly forked in
_Chirothrix_. The small extinct group of _Rhinellidæ_ is usually placed
near the _Myctophidæ_. They are distinguished by the very long gar-like
jaws; whether they possessed adipose fins or luminous spots cannot be
determined. _Rhinellus furcatus_ and other species occur in the
Cretaceous of Europe and Asia. Fossil forms more or less distinctly
related to the _Myctophidæ_ are numerous. _Osmeroides monasterii_
(wrongly called _Sardinioides_), from the German Cretaceous, seems
allied to _Myctophum_, although, of course, luminous spots leave no
trace among fossils. _Acrognathus boops_ is remarkable for the large
size of the eyes.

[Illustration:

  FIG. 95.—_Rhinellus furcatus_ Agassiz. Upper Cretaceous of Mt.
    Lebanon. (After Woodward.)
]

=Maurolicidæ.=—The _Maurolicidæ_ are similar in form and habit, but
scaleless, and with luminous spots more highly specialized. _Maurolicus
pennanti_, the "Sleppy Argentine," is occasionally taken on either side
of the Atlantic. Other genera are _Zalarges_, _Vinciguerria_, and
_Valenciennellus_.

=The Lancet-fishes.=—The _Plagyodontidæ_ (_Alepisauridæ_) contains the
lancet-fishes, large, swift, scaleless fishes of the ocean depths with
very high dorsal fin, and the mouth filled with knife-like teeth. These
large fish are occasionally cast up by storms or are driven to the
shores by the torments of a parasite, _Tetrarhynchus_, found imbedded in
the flesh.

It is probable that they are sometimes killed by being forced above
their level by fishes which they have swallowed. In such cases they are
destroyed through the reduction of pressure.

Every part of the body is so fragile that perfect specimens are rare.
The dorsal fin is readily torn, the bones are very feebly ossified, and
the ligaments connecting the vertebræ are very loose and extensible, so
that the body can be considerably stretched. "This loose connection of
the parts of the body is found in numerous deep-sea fishes, and is
merely the consequence of their withdrawal from the pressure of the
water to which they are exposed in the depths inhabited by them. When
within the limits of their natural haunts, the osseous, muscular, and
fibrous parts of the body will have that solidity which is required for
the rapid and powerful movements of a predatory fish. That the fishes of
this genus (_Plagyodus_) belong to the most ferocious of the class is
proved by their dentition and the contents of their stomach." (Günther.)
Dr. Günther elsewhere observes: "From the stomach of one example have
been taken several octopods, crustaceans, ascidians, a young _Brama_,
twelve young boarfishes (_Capros_), a horse-mackerel, and one young of
its own species."

[Illustration:

  FIG. 96.—Lancet-fish, _Plagyodus ferox_ (Lowe). New York.
]

The lancet-fish, _Plagyodus ferox_, is occasionally taken on either side
of the Atlantic and in Japan. The handsaw-fish, called _Plagyodus
æsculapius_, has been taken at Unalaska, off San Luis Obispo, and in
Humboldt Bay. It does not seem to differ at all from _Plagyodus ferox_.
The original type from Unalaska had in its stomach twenty-one lumpfishes
(_Eumicrotremus spinosus_). This is the species described from Steller's
manuscripts by Pallas under the name of _Plagyodus_. Another species,
_Plagyodus borcalis_, is occasionally taken in the North Pacific.

The _Evermannellidæ_ is a small family of small deep-sea fishes with
large teeth, distensible muscles, and an extraordinary power of
swallowing other fishes, scarcely surpassed by _Chiasmodon_ or
_Saccopharynx_. _Evermannella_ (_Odontostomus_, the latter name
preoccupied) and _Omosudis_ are the principal genera.

The _Paralepidæ_ are reduced allies of _Plagyodus_, slender, silvery,
with small fins and fang-like jaws. As in _Plagyodus_, the adipose fin
is developed and there are small luminous dots. The species are few and
mostly northern; one of them, _Sudis ringens_, is known only from a
single specimen taken by the present writer from the stomach of a hake
(_Merluccius productus_), the hake in turn swallowed whole by an
albacore in the Santa Barbara Channel. The _Sudis_ had been devoured by
the hake, the hake by the albacore, and the albacore taken on the hook
before the feeble _Sudis_ had been digested.

[Illustration:

  FIG. 97.—_Eurypholis sulcidens_ Pictet, restored. Family
    _Enchodontidæ_. Upper Cretaceous of Mt. Lebanon. (After Woodward, as
    _E. boissieri_.)
]

Perhaps allied to the _Plagyodontidæ_ is also the large family of
_Enchodontidæ_, widely represented in the Cretaceous rocks of Syria,
Europe, and Kansas. The body in this group is elongate, the teeth very
strong, and the dorsal fin short. _Enchodus lewesiensis_ is found in
Mount Lebanon, _Halec sternbergi_ in the German Cretaceous, and many
species of _Enchodus_ in Kansas; _Cimolichthys dirus_ in North Dakota.

Remotely allied to these groups is the extinct family of _Dercetidæ_
from the Cretaceous of Germany and Syria. These are elongate fishes, the
scales small or wanting, but with two or more series of bony scutes
along the flanks. In _Dercetis scutatus_ the scutes are large and the
dorsal fin is very long. Other genera are _Leptotrachelus_ and
_Pelargorhynchus_. Dr. Boulenger places the _Dercetidæ_ in the order
_Heteromi_. This is an expression of the fact that their relations are
still unknown. Probably related to the _Dercetidæ_ is the American
family of _Stratodontidæ_ with its two genera, _Stradodus_ and _Empo_
from the Cretaceous (Niobrara) deposits of Kansas. _Empo nepaholica_ is
one of the best-known species.

[Illustration:

  FIG. 98.—_Eurypholis freyeri_ Heckel. Family _Enchodontidæ_.
    Cretaceous. (After Heckel; the restoration of the jaws incorrect.)
]

[Illustration:

  FIG. 99.—_Argyropelecus olfersi_ Cuvier. Gulf Stream.
]

=The Sternoptychidæ.=—The _Sternoptychidæ_ differ materially from all
these forms in the short, compressed, deep body and distorted form. The
teeth are small, the body bright silvery, with luminous spots. The
species live in the deep seas, rising in dark or stormy weather.
_Sternoptyx diaphana_ is found in almost all seas, and species of
_Argyropelecus_ are almost as widely distributed. After the earthquakes
in 1896, which engulfed the fishing villages of Rikuzen, in northern
Japan, numerous specimens of this species were found dead, floating on
the water, by the steamer _Albatross_.

The _Idiacanthidæ_ are small deep-sea fishes, eel-shaped and without
pectorals, related to the _Iniomi_.

=Order Lyopomi.=—Other deep-sea fishes constitute the order or suborder
_Lyopomi_ (λυός, loose; πῶμα, opercle). These are elongate fishes having
no mesocoracoid, and the preopercle rudimentary and connected only with
the lower jaw, the large subopercle usurping its place. The group, which
is perhaps to be regarded as a degenerate type of _Isospondyli_,
contains the single family of _Halosauridæ_, with several species, black
in color, soft in substance, with small teeth and long tapering tail,
found in all seas. The principal genera are _Halosaurus_ and
_Aldrovandia_ (_Halosauropsis_). _Aldrovandia macrochira_ is the
commonest species on our Atlantic coast.

[Illustration:

  FIG. 100.—_Aldrovandia gracilis_ (Goode & Bean). Guadaloupe Island,
    West Indies. Family _Halosauridæ_.
]

Several fossil _Halosauridæ_ are described from the Cretaceous of Europe
and Syria, referred to the genera _Echidnocephalus_ and _Enchelurus_.
Boulenger refers the _Lyopomi_ to the suborder _Heteromi_.



                              CHAPTER VII
                     THE APODES, OR EEL-LIKE FISHES


=THE Eels.=—We may here break the sequence from the _Isospondyli_ to the
other soft-rayed fishes, to interpolate a large group of uncertain
origin, the series or subclass of eels.

The mass of apodal or eel-like fishes has been usually regarded as
constituting a single order, the Apodes (ἄ, without; ποῦς, foot). The
group as a whole is characterized by the almost universal separation of
the shoulder-girdle from the skull, by the absence of the mesocoracoid
arch on the shoulder-girdle, by the presence of more than five pectoral
actinosts, as in the Ganoid fishes, by the presence of great numbers of
undifferentiated vertebræ, giving the body a snake-like form, by the
absence in all living forms of the ventral fins, and, in all living
forms, by the absence of a separate caudal fin. These structures
indicate a low organization. Some of them are certainly results of
degeneration, and others are perhaps indications of primitive
simplicity. Within the limits of the group are seen other features of
degeneration, notably shown in the progressive loss of the bones of the
upper jaw and the membrane-bones of the head and the degradation of the
various fins. The symplectic bone is wanting, the notochord is more or
less persistent, the vertebral centra always complete constricted
cylinders, none coalesced. But, notwithstanding great differences in
these regards, the forms have been usually left in a single order, the
more degraded forms being regarded as descended from the types which
approach nearest to the ordinary fishes. From this view Professor Cope
dissents. He recognizes several orders of eels, claiming that we should
not unite all these various fishes into a single order on account of the
eel-like form. If we do so, we should place in another order those with
the fish-like form. It is probable, though not absolutely certain, that
the _Apodes_ are related to each other. The loss among them, first, of
the connection of the post-temporal with the skull; second, of the
separate caudal fin and its hypural support; third, of the distinct
maxillary and premaxillary; and fourth, of the pectoral fins, must be
regarded as successive phases of a general line of degradation. The
large number of actinosts, the persistence of the notochord, the absence
of spines, and the large numbers of vertebræ seem to be traits of
primitive simplicity. Special lines of degeneration are further shown by
deep-sea forms. What the origin of the _Apodes_ may have been is not
known with any certainty. They are soft-rayed fishes, with the
air-bladder connected by a tube with the œsophagus, and with the
anterior vertebræ not modified. In so far they agree with the
_Isospondyli_. In some other respects they resemble the lower
_Ostariophysi_, especially the electric eel and the eel-like catfishes.
But these resemblances, mainly superficial, may be wholly deceptive; we
have no links which certainly connect the most fish-like Apodes with any
of the other orders. Probably Woodward's suggestion that they may form a
series parallel with the _Isospondyli_ and independently descended from
Tertiary Ganoids deserves serious consideration. Perhaps the most
satisfactory arrangement of these fishes will be to regard them as
constituting four distinct orders for which we may use the names
_Symbranchia_ (including _Ichthyocephali_ and _Holostomi_), _Apodes_
(including _Enchelycephali_ and _Colocephali_), _Carencheli_, and
_Lyomeri_.

=Order Symbranchia.=—The _Symbranchia_ are distinguished by the
development of the ordinary fish mouth, the maxillary and premaxillary
being well developed. The gill-openings are very small, and usually
confluent below. These fresh-water forms of the tropics, however
eel-like in form, may have no real affinity with the true eels. In any
event, they should not be placed in the same order with the latter.

The eels of the suborder _Ichthyocephali_ (ιχθύς, fish; κεφαλή, head)
have the head distinctly fish-like. The maxillary, premaxillary, and
palatines are well developed, and the shoulder-girdle is joined by a
post-temporal to the skull. The body is distinctly eel-like, the tail
being very short and the fins inconspicuous. The number of vertebræ is
unusually large. The order contains the single family _Monopteridæ_, the
rice-field eels, one species, _Monopterus albus_, being excessively
common in pools and ditches from China and southern Japan to India.

The eels of the suborder _Holostomi_ (ὀλός, complete; στόμα, mouth)
differ from these mainly in the separation of the shoulder-girdle from
the skull, a step in the direction of the true eels. The _Symbranchidæ_
are very close to the _Monopteridæ_ in external appearance, small,
dusky, eel-like inhabitants of sluggish ponds and rivers of tropical
America and the East Indies. The gill-openings are confluent under the
throat. _Symbranchus marmoratus_ ranges northward as far as Vera Cruz,
having much the habit of the rice-field eel of Japan and China. The
_Amphipnoidæ_, with peculiar respiratory structures, abound in India.
_Amphipnous cuchia_, according to Günther, has but three gill-arches,
with rudimentary lamina and very narrow slits. To supplement this
insufficient branchial apparatus, a lung-like sac is developed on each
side of the body behind the head, opening between the hyoid and the
first branchial arch. The interior of the sac is abundantly provided
with blood-vessels, the arterial coming from the branchial arch, whilst
those issuing from it unite to form the aorta. _Amphipnous_ has
rudimentary scales. The other _Holostomi_ and _Ichthyocephali_ are naked
and all lack the pectoral fin.

The _Chilobranchidæ_ are small sea-fishes from Australia, with the tail
longer than the rest of the body, instead of much shorter as in the
others.

No forms allied to _Symbranchus_ or _Monopterus_ are recorded as
fossils.

=Order Apodes, or True Eels.=—In this group the shoulder-girdle is free
from the skull, and the bones of the jaws are reduced in number, through
coalescence of the parts.

Three well-marked suborders may be recognized, groups perhaps worthy of
still higher rank: _Archencheli_, _Enchelycephali_, and _Colocephali_.

=Suborder Archencheli.=—The _Archencheli_, now entirely extinct, are
apparently the parents of the eels, having, however, certain traits
characteristic of the _Isospondyli_. They retain the separate caudal
fin, with the ordinary hypural plate, and Professor Hay has recently
found, in an example from the Cretaceous of Mount Lebanon, remains of
distinct ventral fins. These traits seem to indicate an almost perfect
transition from the _Isospondyli_ to the _Archencheli_.

One family may be recognized at present, _Urenchelyidæ_.

The earliest known eel, _Urenchelys avus_, occurs in the upper
Cretaceous at Mount Lebanon. It represents the family _Urenchelyidæ_,
apparently allied to the _Anguillidæ_, but having a separate caudal fin.
Its teeth are small, conical, blunt, in many series. There are more than
100 vertebræ, the last expanded in a hypural. Pectorals present. Scales
rudimentary; dorsal arising at the occiput. Branchiostegals slender, not
curved around the opercle. _Urenchelys anglicus_ is another species,
found in the chalk of England.

=Suborder Enchelycephali.=—The suborder _Enchelycephali_ (ἔγχελυς, eel;
κεφαλή, head) contains the typical eels, in which the shoulder-girdle is
free from the skull, the palatopterygoid arch relatively complete, the
premaxillaries wanting or rudimentary, the ethmoid and vomer coalesced,
forming the front of the upper jaw, the maxillaries lateral, and the
cranium with a single condyle. In most of the species pectoral fins are
present, and the cranium lacks the combined degradation and
specialization shown by the morays (_Colocephali_).

=Family Anguillidæ.=—The most primitive existing family is that of the
typical eels, _Anguillidæ_, which have rudimentary scales oblong in
form, and set separately in groups at right angles with one another.
These fishes are found in the fresh and brackish waters of all parts of
the world, excepting the Pacific coast of North America and the islands
of the Pacific. In the upper Great Lakes and the upper Mississippi they
are also absent unless introduced. The species usually spawn in the sea
and ascend the rivers to feed. But some individuals certainly spawn in
fresh water, and none go far into the sea, or where the water is
entirely salt. The young eels sometimes ascend the brooks near the sea
in incredible numbers, constituting what is known in England as
"eel-fairs." They will pass through wet grass to surmount ordinary
obstacles. Niagara Falls they cannot pass, and according to Professor
Baird "in the spring and summer the visitor who enters under the sheet
of water at the foot of the falls will be astonished at the enormous
numbers of young eels crawling over the slippery rocks and squirming in
the seething whirlpools. An estimate of hundreds of wagon-loads, as seen
in the course of the perilous journey referred to, would hardly be
considered excessive by those who have visited the spot at a suitable
season of the year." "At other times large eels may be seen on their way
down-stream, although naturally they are not as conspicuous then as are
the hosts of the young on their way upstream. Nevertheless it is now a
well-assured fact that the eels are catadromous, that is, that the old
descend the watercourses to the salt water to spawn, and the young, at
least of the female sex, ascend them to enjoy life in the fresh water."

[Illustration:

  FIG. 101.—Common Eel, _Anguilla chrisypa_ Rafinesque. Holyoke, Mass.
]

=Reproduction of the Eel.=—Dr. Gill ("Riverside Natural History," p.
103) gives the following account of the reproduction of _Anguilla_:

"The generation of the eel was long involved in great mystery, and the
knowledge thereof is one of the recent acquisitions of scientific
investigation. So late, indeed, as 1880 it was declared that 'their mode
of propagation is still unknown.' In want of positive knowledge the rein
has been given to loose hypothesis and conjecture. It has been variously
asserted that eels were generated from slime, from dew, and from the
skins of old eels or of snakes. The statement that they come from
horse-hairs is familiar to many country boys, and the origin of this
belief is due simply to the fact that there are certain aquatic worms,
known under the generic name _Gordius_, which are elongated and
apparently smooth like the eel, and which may be found in the same
waters. It was one of the ideas of the Greek to attribute their
paternity, as of many other doubtful offspring, to the convenient
Jupiter. The statement that they are viviparous has arisen from two
causes: one the existence of intestinal worms, and the other from the
confusion of the eel with an elongated and consequently eel-like but
otherwise very different form, the _Zoarces viviparus_. The _Zoarces_ is
indeed, in Germany as well as in the Scandinavian countries, generally
known as the Aal-mutter, or eel-mother, and thus in its name perpetuates
the fancy. Even where eels are to be found in extreme abundance, and
where they are the objects of a special culture, like erroneous opinions
prevail. Thus, according to Jacoby, about the lagoon of Comacchio there
is an 'ineradicable belief among the fishermen that the eel is born of
other fishes; they point to special differences in color and especially
in the common mullet, _Mugil cephalus_, as the causes of variation in
color and form among eels. It is a very ancient belief, widely prevalent
to the present day, that eels pair with water-snakes. In Sardinia the
fishermen cling to the belief that a certain beetle, the so-called
water-beetle, _Dytiscus ræselii_, is the progenitor of eels, and they
therefore call this "mother of eels."' The assignment of such maternity
to the water-beetle is doubtless due to the detection of the hair-worm,
or Gordius, in the insect by sharp-sighted but unscientific observers,
and, inasmuch as the beetle inhabits the same waters as the eel, a very
illogical deduction has led to connect the two together.

"All such beliefs as have been thus recounted are due to the
inconspicuous nature of the generative organs in eels found in fresh
waters and at most seasons—a characteristic which is in strong contrast
to the development of corresponding parts in fishes generally.
Nevertheless the ovaries of the eel were discovered, as long ago as
1707, by Dr. Sancassini of Comacchio, and described by the celebrated
Valisneri (after whom the plant _Valisneria_ was named) in 1710, again
by Mondini in 1777, and almost contemporaneously by O. J. Müller of
Denmark. Later the illustrious Rathke (in 1824, 1838, and 1850) and also
Hornbaum-Hornschuch published the results of special investigations, and
figured the eggs. But it was only in 1873 (after several futile
endeavors by others) that the male organ of the eel was recognized, also
by an Italian naturalist, Dr. Syrski, in small individuals of the
species, and a previous idea that the eel was hermaphroditic thereby
dispelled. The sexual differences are correlated with external ones, and
generally the males and females, when adult, can be told apart. Jacoby
testifies that he examined large numbers with a view to solve this
question. The most important differences relate to (1) size; (2) form of
the snout; (3) color; (4) dorsal fin; and (5) size of the eyes. (1) The
males rarely attain a length of more than seventeen to nineteen inches,
while adult females are generally much larger; (2) the snout in the male
is attenuated and rather pointed, while in the female it is
comparatively broad and blunt; (3) the male is of a deep darkish green,
or often a deep black with a shining luster and a whitish belly, while
the female has a clearer color, usually of a greenish hue on the back
and yellowish on the belly; (4) the dorsal fin is lower and less
developed in the male than in the female; and (5) the eye of the male is
large and that of the female, as a rule, comparatively small. These
characters, however, do not always hold good. Jacoby remarked that
'special reference having been paid to the height and narrowness of the
dorsal fin, much success has been met with in picking out, in the
fish-market of Trieste, the eels which possessed the organ of Syrski
(that is, the male organ); absolute certainty, however, in recognizing
them cannot be guaranteed. If one is searching among living eels with no
characters in mind,—with the exception of the first, that of length,—he
will find in every ten eels, on an average, eight females and two with
the supposed male organ; but if the selection is made with a careful
reference to all these marks of difference, the proportion changes, and
out of every ten examples about eight will be found with the supposed
male organ.'

"According to Herr Benecke, 'it may be assumed with the greatest safety
that the eel lays its eggs like most other fish, and that, like the
lamprey, it spawns only once and then dies. All the eggs of a female
show the same degree of maturity, while in the fish which spawn every
year, besides the large eggs which are ready to be deposited at the next
spawning period, there exist very many of much smaller size, which are
destined to mature hereafter and be deposited in other years. It is very
hard to understand how young eels could find room in the body of their
mother if they were retained until they had gained any considerable
size. The eel embryo can live and grow for a long time supported by the
little yolk, but, when this is done, it can only obtain food outside of
the body of its mother. The following circumstances lead us to believe
that the spawning of the eel takes place only in the sea: (1) that the
male eel is found only in the sea or brackish water, while female eels
yearly undertake a pilgrimage from the inland waters to the sea, a
circumstance which has been known since the time of Aristotle, and upon
the knowledge of which the principal capture of eels by the use of fixed
apparatus is dependent; (2) that the young eels, with the greatest
regularity, ascend from the sea into the rivers and lakes.'"

All statements in opposition to this theory are untenable, since the
young eels never find their way into landlocked ponds in the course of
their wanderings, while eels planted in such isolated bodies of water
thrive and grow rapidly, but never increase in numbers. Another still
more convincing argument is the fact that in lakes which formerly
contained many eels, but which, by the erection of impassable weirs,
have been cut off from the sea, the supply of eels has diminished, and
after a time only scattering individuals, old and of great size, are
taken in them. An instance of this sort occurred in Lake Muskengorf in
West Prussia. If an instance of the reproduction of the eel in fresh
water could be found, such occurrences as these would be quite
inexplicable.

In the upper stretches of long rivers the migration of the eels begins
in April or in May; in their lower stretches and shorter streams, later
in the season. In all running waters the eel-fishery depends upon the
downward migrations; the eels press up the streams with occasional
halts, remaining here and there for short periods, but always make their
way above. They appear to make the most progress during dark nights,
when the water is troubled and stormy, for at this time they are
captured in the greatest numbers. It is probable that after the eels
have once returned to the sea and there deposited their spawn, they
never can return into fresh water, but remain there to die. A great
migration of grown eels in spring or summer has never been reported, and
it appears certain that all the female eels which have once found their
way to the sea are lost to the fisherman.

=Food of the Eel.=—Eels, in the words of Mr. W. H. Ballou, are "among
the most voracious of carnivorous fishes. They eat most inland fishes,
except the garfish and the chub. Investigation of six hundred stomachs
by Oswego fishermen showed that the latter bony fish never had a place
in their bill of fare. They are particularly fond of game-fishes, and
show the delicate taste of a connoisseur in their selection from choice
trout, bass, pickerel, and shad. They fear not to attack any object when
disposed, and their bite in human flesh shows even a vicious attitude
towards man. On their hunting excursions they overturn huge and small
stones alike, working for hours if necessary, beneath which they find
species of shrimp and crayfish, of which they are exceedingly fond. Of
shrimps they devour vast numbers. Their noses are poked into every
imaginable hole in their search for food, to the terror of innumerable
small fishes."

In the opinion of Mr. Ballou, too, "eels are to the water what the
fishhawk is to the air. They are, perhaps, the most powerful and rapid
of natatorians. Again, they hide in the mud beneath some log or
overhanging rock, and dart out with tremendous fury at the unsuspecting
prey. They attack the spawn of other fishes open-mouthed, and are even
said to suck the eggs from an impaled female. They fearlessly and
rapidly dive head-foremost in the mud, disappearing from view in the
twinkling of a star. They are owl-like in their habits, committing many
of their depredations at night.

"No fish is yet reported to utilize a full-grown eel as food. Pickerel,
garfish, and bass, which are particularly numerous in these lakes, are
supposed to literally devour the young fry. Mr. Sawyer describes the
operation of the pickerel darting through a long column of young eels
open-mouthed and devouring vast numbers of them."

=Larva of the Eel.=—The translucent band-shaped larva of the common eel
has been very recently identified and described by Dr. Eigenmann. It is
probable that all true eels, _Enchelycephali_, pass through a
band-shaped or leptocephalous stage, as is the case with _Albula_ and
other _Isospondyli_. In the continued growth the body becomes firmer,
and at the same time much shorter and thicker, gradually assuming the
normal form of the species in question.

[Illustration:

  FIG. 102.—Larva of Common Eel, _Anguilla chrisypa_ (Rafinesque),
    called _Leptocephalus grassii_. (After Eigenmann.)
]

In a recent paper Dr. Carl H. Eigenmann has very fully reviewed the
life-history of the eel. The common species live in fresh waters,
migrating to the sea in the winter. They deposit in deep water minute
eggs that float at the surface. The next year they develop into the
band-shaped larva. The young eels enter the streams two years after
their parents drop down to the sea. It is doubtful whether eels breed in
fresh water. The male eel is much smaller than the female.

The eel is an excellent food-fish, the flesh being tender and oily, of
agreeable flavor, better than that of any of its relatives. Eels often
reach a large size, old individuals of five or six feet in length being
sometimes taken.

=Species of Eels.=—The different species are very closely related. Not
more than four or five of them are sharply defined, and these mostly in
the South Seas and in the East Indies. The three abundant species of the
north temperate zone, _Anguilla anguilla_ of Europe, _Anguilla chrisypa_
of the eastern United States, and _Anguilla japonica_ of Japan, are
scarcely distinguishable. In color, size, form, and value as food they
are all alike.

Fossil species referred to the _Anguillidæ_ are known from the early
Tertiary. _Anguilla leptoptera_ occurs in the Eocene of Monte Bolea, and
_Anguilla elegans_ in the Miocene of Œningen in Baden. Other fossil eels
seem to belong to the _Nettastomidæ_ and _Myridæ_.

=Pug-nosed Eels.=—Allied to the true eel is the pug-nosed eel,
_Simenchelys parasiticus_, constituting the family of _Simenchelyidæ_.
This species is scaled like a true eel, has a short, blunt nose, and
burrows its way into the bodies of halibut and other large fishes. It
has been found in Newfoundland and Madeira. Another family possessing
rudimentary scales is that of the _Synaphobranchidæ_, slender eels of
the ocean depths, widely distributed. In these forms the gill-openings
are confluent. _Synaphobranchus pinnatus_ is the best-known species.

[Illustration:

  FIG. 103.—Pug-nosed Eel, _Simenchelys parasiticus_ Gill. Sable Island
    Bank.
]

[Illustration:

  FIG. 104.—_Synaphobranchus pinnatus_ (Gronow). Le Have Bank.
]

=Conger-eels.=—The _Leptocephalidæ_, or conger-eels, are very similar to
the fresh-water eels, but are without scales and with a somewhat
different mouth, the dorsal beginning nearer to the head.

The principal genus is _Leptocephalus_, including the common conger-eel
(_Leptocephalus conger_) of eastern America and Europe and numerous very
similar species in the tropics of both continents. These fishes are
strictly marine and, reaching the length of five or six feet, are much
valued as food. The eggs are much larger than those of the eel and are
produced in great numbers, so that the female almost bursts with their
numbers. Dr. Hermes calculated that 3,300,000 were laid by one female in
an aquarium.

These eggs hatch out into transparent band-like larva, with very small
heads formerly known as _Leptocephalus_, an ancient name which is now
taken for the genus of congers, having been first used for the larva of
the common conger-eel. The loose watery tissues of these "ghost-fishes"
grow more and more compact and they are finally transformed into young
congers.

[Illustration:

  FIG. 105.—Conger-eel, _Leptocephalus conger_ (L.). Noank, Conn.
]

The _Murænesocidæ_ are large eels remarkable for their strong knife-like
teeth. _Murænesox savanna_ occurs in the West Indies and in the
Mediterranean, _Murænesox cinereus_ in Japan, and _Murænesox coniceps_
on the west coast of Mexico, all large and fierce, with teeth like
shears. The _Myridæ_ are small and worm-like eels closely allied to the
congers, having the tail surrounded by a fin, but the nostrils labial.
_Myrus myrus_ is found in the Mediterranean. Species of _Eomyrus_,
_Rhynchorhinus_, and _Paranguilla_ apparently allied to _Myrus_ occur in
the Eocene. Other related families, mostly rare or living in the deep
seas, are the _Ilyophidæ_, _Heterocongridæ_, and _Dysommidæ_.

[Illustration:

  FIG. 106.—Larva of Conger-eel (_Leptocephalus conger_), called
    _Leptocephalus morrissi_. (After Eigenmann.)
]

=The Snake-eels.=—Most varied of the families of eels is the
_Ophichthyidæ_, snake-like eels recognizable by the form of the tail,
which protrudes beyond the fins. Of the many genera found in tropical
waters several are remarkable for the sharply defined coloration,
suggesting that of the snake. Characteristic species are _Chlevastes
colubrinus_ and _Leiuranus semicinctus_, two beautifully banded species
of Polynesia, living in the same holes in the reefs and colored in the
same fashion. Another is _Callechelys melanotænia_. The commonest
species on the Atlantic coast is the plainly colored _Ophichthus
gomesi_.

[Illustration:

  FIG 107.—_Xyrias revulsus_ Jordan & Snyder. Family _Ophichthyidæ_.
    Misaki, Japan.
]

In the genus _Sphagebranchus_, very slender eels of the reefs, the fins
are almost wanting.

[Illustration:

  FIG. 108.—_Myrichthys pantostigmius_ Jordan & McGregor. Clarion
    Island.
]

[Illustration:

  FIG. 109.—_Ophichthus ocellatus_ (Le Sueur). Pensacola.
]

Allied to the Congers is the small family of duck-billed eels
(_Nettastomidæ_) inhabiting moderate depths of the sea. _Nettastoma
bolcense_ occurs in the Eocene of Monte Bolca. The produced snout forms
a transition to the really extraordinary type of thread-eels or
snipe-eels (_Nemichthyidæ_), of which numerous genera and species live
in the oceanic depths. In _Nemichthys_ the long, very slender,
needle-like jaws are each curved backward so that the mouth cannot by
any possibility be shut. The body is excessively slender and the fish
swims with swift undulations, often near the surface, and when seen is
usually taken for a snake. The best-known species is _Nemichthys
scolopaceus_ of the Atlantic and Pacific. _Nemichthys avocetta_, very
much like it, has been twice taken in Puget Sound.

[Illustration:

  FIG. 110.—Thread-eel, _Nemichthys avocetta_ Jordan & Gilbert.
    Vancouver Island.
]

=Suborder Colocephali, or Morays.=—In the suborder _Colocephali_ (κολός,
deficient; κεφαλή, head) the palatopterygoid arch and the membrane-bones
generally are very rudimentary. The skull is thus very narrow, the
gill-structures are not well developed, and in the chief family there
are no pectoral fins. This group is very closely related to the
_Enchelycephali_, from which it is probably derived.

[Illustration:

  FIG. 111.—Jaws of _Nemichthys avocetta_ Jordan & Gilbert.
]

In the great family of morays (_Murænidæ_) the teeth are often very
highly developed. The muscles are always very strong and the spines bite
savagely, a live moray being often able to drive men out of a boat. The
skin is thick and leathery, and the coloration is highly specialized,
the pattern of color being often elaborate and brilliant. In _Echidna
zebra_ for example the body is wine-brown, with cross-stripes of golden
yellow. In _Muræna_ each nostril has a barbel. _Muræna helena_, the
oldest moray known, is found in Europe. In _Gymnothorax_, the largest
genus, only the anterior nostrils are thus provided. _Gymnothorax
mordax_ of California is a large food-fish, as are also the brown
_Gymnothorax funebris_ and the spotted _Gymnothorax moringa_ in the West
Indies. These and many other species may coil themselves in crevices in
the reefs, whence they strike out at their prey like snakes, taking
perhaps the head of a duck or the finger of a man.

In many of the morays the jaws are so curved and the mouth so filled
with knife-like teeth that the jaws cannot be closed. This fact,
however, renders no assistance to their prey, as the teeth are adapted
for holding as well as for cutting.

In _Enchelynassa bleekeri_, a huge wine-colored eel of the South Seas,
the teeth are larger than in any other species. _Evenchelys_
(_macrurus_) is remarkable for its extraordinary length of tail,
_Echidna_ for its blunt teeth, and _Scuticaria_, _Uropterygius_, and
_Channomuræna_ for the almost complete absence of fins. In _Anarchias_
(_allardicei_; _knighti_), the anal fin is absent. The flesh of the
morays is rather agreeable in taste, but usually oily and not readily
digestible, less wholesome than that of the true eels.

[Illustration:

  FIG. 112.—_Muræna retifera_ Garman. Charleston, S. C.
]

The _Myrocongridæ_ are small morays with developed pectoral fins. The
species are few and little known.

=Family Moringuidæ.=—Structurally one of the most peculiar of the groups
of eels is the small family of _Moringuidæ_ of the East and West Indies.
In these very slender, almost worm-like fishes the heart is placed very
far behind the gills and the tail is very short. The fins are very
little developed, and some forms, as _Gordiichthys irretitus_ of the
Gulf of Mexico, the body as slender as a whiplash, possess a very great
number of vertebræ. _Moringua hawaiiensis_ occurs in Hawaii, _M.
edwardsi_ in the Bahamas. This family probably belongs with the morays
to the group of _Colocephali_, although its real relationships are not
wholly certain.

=Order Carencheli, the Long-necked Eels.=—Certain offshoots from the
Apodes so widely diverging in structure that they must apparently be
considered as distinct orders occur sparingly in the deep seas. One of
these, _Derichthys serpentinus_, the long-necked eel, constitutes the
sole known species of the suborder _Carencheli_ (καρά, head; ἔγχελυς,
eel). In this group the premaxillaries and maxillaries are present as in
ordinary fishes, but united by suture and soldered to the cranium. As in
true eels, the shoulder-girdle is remote from the skull. The head is set
on a snake-like neck. The single species representing the family
_Derichthyidæ_ was found in the abysmal depths of the Gulf Stream.

[Illustration:

  FIG. 113.—_Gymnothorax berndti_ Snyder. Hawaii. Family _Murænidæ_.
]

[Illustration:

  FIG. 114.—_Gymnothorax jordani_ (Evermann & Marsh). Family _Murænidæ_.
    Puerto Rico.
]

[Illustration:

  FIG. 115.—Moray, _Gymnothorax moringa_ Bloch. Family _Murænidæ_.
    Tortugas.
]

[Illustration:

  FIG. 116.—_Derichthys serpentinus_ Gill. Gulf Stream.
]

[Illustration:

  FIG. 117.—Gulper-eel, _Gastrostomus bairdi_ Gill & Ryder. Gulf Stream.
]

=Order Lyomeri, or Gulpers.=—Still more aberrent and in many respects
extraordinary are the eels of the order or suborder _Lyomeri_ (λυός,
loose; μέρος, part), known as "Gulpers." These are degenerate forms,
possibly degraded from some conger-like type, but characterized by an
extreme looseness of structure unique among fishes. The gill-arches are
reduced to five small bars of bone, not attached to the skull, the
palatopterygoid arch is wholly wanting, the premaxillaries are wanting,
as in all true eels, and the maxillaries loosely joined to the skull.
The symplectic bone is wanting, and the lower jaw is so hinged to the
skull that it swings freely in various directions. In place of the
lateral line are singular appendages. Dr. Gill says of these fishes:
"The entire organization is peculiar to the extent of anomaly, and our
old conceptions of the characteristics of a fish require to be modified
in the light of our knowledge of such strange beings." Special features
are the extraordinary size of the mouth, which has a cavity larger than
that of the rest of the body, the insertion of the very small eye at the
tip of the snout, and the relative length of the tail. The whole
substance is excessively fragile as usual with animals living in great
depths and the color is jet black. Three species have been described,
and these have been placed in two families, _Saccopharyngidæ_, with the
trunk (gill-opening to the vent) much longer than the head, and
_Eurypharyngidæ_, with the trunk very short, much shorter than the head.
The best-known species is the pelican eel (_Eurypharynx pelacanoides_),
of the coast of Morocco, described by Vaillant in 1882. _Gastrostomus
bairdi_, very much like it, occurs in the great depths under the Gulf
Stream. So fragile and so easily distorted are these fishes that it is
possible that all three are really the same species, for which the
oldest name would be _Saccopharynx ampullaceus_. Of this form four
specimens have been taken in the Atlantic, one of them six feet long,
carried to the surface through having swallowed fishes too large to be
controlled. To be carried above its depth in a struggle with its prey is
one of the greatest dangers to which the abysmal fishes are subject.

=Order Heteromi.=—The order of _Heteromi_ (ἑτερός, different; ὤμος,
shoulder), or spiny eels, may be here noticed for want of a better
place, as its affinities are very uncertain. Some writers have regarded
it as allied to the eels; some have placed it among the Ganoids. Others
have found affinities with the sticklebacks, and still others with the
singular fresh-water fishes called _Mastacembelus_. The _Heteromi_ agree
with the eels, as well as with _Mastacembelus_, in having the scapular
arch separate from the cranium. Unlike all the true eels, most of the
species have true dorsal and anal spines, as in the _Percesoces_ and
_Hemibranchii_. The ventral fins, when present, are abdominal and each
with several spines in front, a character not found among the
_Acanthopteri_. There is no mesocoracoid.

The air-bladder has a duct, and the coracoids, much as in the _Xenomi_,
are reduced to a single lamellar imperforate plate. The two groups have
little else in common, however, and this trait is possibly primitive in
both cases, more likely to have arisen through independent degeneration.
The separation of the shoulder-girdle doubtless indicates no affinity
with the eels, as the bones of the jaws are quite normal. Two families
are known, both from the deep sea, besides an extinct family in which
spines are not developed.

The _Notacanthidæ_ are elongate, compressed, ending in a band-shaped,
tapering tail; the back has numerous free spines and few or no soft
rays, and the mouth is normal, provided with teeth. The species of
_Notacanthus_ are few and scantily preserved. Those of _Macdonaldia_ are
more abundant. _Macdonaldia challengeri_ is from the North Pacific,
being once taken off Tokio. The extinct family of _Protonotacanthidæ_
differs in the total absence of dorsal spines and fin-rays; the single
species, _Pronotocanthus sahel-almæ_, originally described as a
primitive eel, occurs in the Cretaceous of Mount Lebanon.

The _Lipogenyidæ_ have a round, sucker-like mouth, with imperfect lower
jaw, but are otherwise similar. _Lipogenys gilli_ was dredged in the
Gulf Stream.

[Illustration:

  FIG. 118.—_Notacanthus phasganorus_ Goode & Bean. Grand Banks.
]

Dr. Boulenger has recently extended the group of _Heteromi_ by the
addition of the _Dercetidæ_, _Halosauridæ_ (_Lyopomi_), and the
_Fierasferidæ_. We can hardly suppose that all these forms are really
allied to _Notacanthus_.



                              CHAPTER VIII
                          SERIES OSTARIOPHYSI


=OSTARIOPHYSI.=—A large group of orders, certainly of common descent,
may be brought together under the general name of _Ostariophysi_
(ὀσταρίον, a small bone; θυσός, inflated). These are in many ways allied
to the _Isospondyli_, but they have undergone great changes of
structure, some of the species being highly specialized, others
variously degenerate. A chief character is shared by all the species.
The anterior vertebræ are enlarged, interlocked, considerably modified,
and through them a series of small bones connect the air-bladder with
the ear. The air-bladder thus becomes apparently an organ of hearing
through a form of connection which is lost in all the higher fishes.

In all the members of this group excepting perhaps the degraded eel-like
forms called _Gymnonoti_, the mesocoracoid arch persists, a trait found
in all the living types of Ganoids, as well as in the _Teleost_ order of
_Isospondyli_. Other traits of the Ostariophysan fishes are shared by
the _Isospondyli_ (herring, salmon) and other soft-rayed fishes. The
air-bladder is large, but not cellular. It leads through life by an open
duct to the œsophagus. The ventral fins are abdominal in position. The
pectorals are inserted low. A mesocoracoid arch is developed on the
inner side of the shoulder-girdle. (See Fig. 119.) There are no spines
on the fins, except in many cases a single one, a modified soft ray at
front of dorsal or pectoral. The scales, if present, are cycloid or
replaced by bony plates.

Many of the species have an armature much like that of the sturgeon, but
here the resemblance ends, the bony plates in the two cases being
without doubt independently evolved. According to Cope, the affinities
of the catfishes to the sturgeon are "seen in the absence of symplectic,
the rudimentary maxillary bone, and, as observed by Parker, in the
interclavicles. There is also a superficial resemblance in the dermal
bones." But it is not likely that any real affinity exists.

[Illustration:

  FIG. 119.—Inner view of shoulder-girdle of the Buffalo-fish. _Ictiobus
    bubalus_ Rafinesque, showing the mesocoracoid (59). (After Starks.)
]

The sturgeons lack the characteristic auditory ossicles, or "Weberian
apparatus," which the catfishes possess in common with the carp family,
the _Characins_, and the _Gymnonoti_. These orders must at least have a
common origin, although this origin is obscure, and fossil remains give
little help to the solution of the problem. Probably the ancestors of
the _Ostariophysi_ are to be found among the allies of the
_Osteoglossidæ_. Gill has called attention to the resemblance of
_Erythrinus_ to _Amia_. In any event, all the _Ostariophysi_ must be
considered together, as it is not conceivable that so complex a
structure as the Weberian apparatus should have been more than once
independently evolved. The branchiostegals, numerous among the
_Isospondyli_, are mostly few among the _Ostariophysi_.

[Illustration:

  FIG. 120.—Weberian apparatus and air-bladder of Carp. (From Günther,
    after Weber.)
]

To the _Ostariophysi_ belong the vast majority of the fresh-water fishes
of the world. Their primitive structure is shown in many ways; among
others by the large number of vertebræ instead of the usual twenty-four
among the more highly specialized families of fishes. We may group the
_Ostariophysi_ under four orders: _Heterognathi_, _Eventognathi_
(_Plectospondyli_), _Nematognathi_, and _Gymnonoti_.

=The Heterognathi.=—Of these the order of _Heterognathi_ seems to be the
most primitive, but in some ways the most highly developed, showing
fewer traits of degeneration than any of the others. The presence of the
adipose fin in this group and in the catfishes seems to indicate some
sort of real affinity with the salmon-like forms, although there has
been great change in other regards.

The order _Heterognathi_, or _Characini_ (ἕτερος, different; γνάθος,
jaw), contains those _Ostariophysi_ which retain the mesocoracoid and
are not eel-like, and which have the lower pharyngeals developed as in
ordinary fishes. In most cases an adipose fin is present and there are
strong teeth in the jaws. There are no pseudobranchiæ, and, as in the
_Cyprinidæ_, usually but three branchiostegals. The _Characidæ_
constitute the majority of the fresh-water fishes in those regions which
have neither _Cyprinidæ_ nor _Salmonidæ_. Nearly four hundred species
are known from the rivers of South America and Africa. A single species,
_Tetragonopterus argentatus_, extends its range northward to the Rio
Grande in Texas. None are found in Asia, Europe, or, with this single
exception, in the United States. Most of them are small fishes with deep
bodies and very sharp, serrated, incisor-like teeth. Some are as
innocuous as minnows, which they very much resemble, but others are
extremely voracious and destructive in the highest degree. Of the
caribe, belonging to the genus _Serrasalmo_, known by its serrated
belly, Dr. Günther observes:

"Their voracity, fearlessness and number render them a perfect pest in
many rivers of tropical America. In all the teeth are strong, short,
sharp, sometimes lobed incisors, arranged in one or more series; by
means of them they cut off a mouthful of flesh as with a pair of
scissors; and any animal falling into the water where these fish abound
is immediately attacked and cut to pieces in an incredibly short time.
They assail persons entering the water, inflicting dangerous wounds
before the victims are able to make their escape. In some localities it
is scarcely possible to catch fishes with the hook and line, as the fish
hooked is immediately attacked by the 'caribe' (as these fish are
called), and torn to pieces before it can be withdrawn from the water.
The caribes themselves are rarely hooked, as they snap the hook or cut
the line. The smell of blood is said to attract at once thousands of
these fishes to the spot."

Two families of _Heterognathi_ are recognized: the _Erythrinidæ_, which
lack the adipose fin, and the _Characidæ_, in which this fin is
developed. The _Erythrinidæ_ are large pike-like fishes of the South
American rivers, robust and tenacious of life, with large mouths armed
with strong unequal teeth. The best-known species is the _Trahira_
(_Hoplias malabaricus_).

[Illustration:

  FIG. 121.—_Brycon dentex_ Günther. Family _Characidæ_. Nicaragua.
]

Among the _Characidæ_, _Serrasalmo_ has been already noticed.
_Citharinus_ in Africa has very few teeth, and _Curimatus_ in South
America none at all. _Nannocharax_ in Africa is composed of very
diminutive fishes, _Hydrocyon_ exceedingly voracious ones, reaching a
length of four feet, with savage teeth. Many of the species are allies
of _Tetragonopterus_, small, silvery, bream-like fishes with flat bodies
and serrated incisor teeth. Most of these are American. A related genus
is _Brycon_, found in the streams about the Isthmus of Panama.

Extinct _Characins_ are very rare. Two species from the Tertiary lignite
of São Paulo, Brazil, have been referred to _Tetragonopterus_—_T. avus_
and _T. ligniticus_.

=The Eventognathi.=—The _Eventognathi_ (ἔυ, well; ἔν, within; γνάθος,
jaw) are characterized by the absence of teeth in the jaws and by the
high degree of specialization of the lower pharyngeals, which are
scythe-shaped and in typical forms are armed with a relatively small
number of highly specialized teeth of peculiar shape and arranged in
one, two, or three rows. In all the species the gill-openings are
restricted to the sides; there is no adipose fin, and the broad, flat
branchiostegals are but three in number. In all the species the scales,
if present, are cycloid, and the ventral fins, of course, abdominal. The
modification of the four anterior vertebræ and their connection with the
air bladder are essentially as seen in the catfishes.

The name _Plectospondyli_ is often used for this group (πλεκτός,
interwoven; σπόνδυλος, vertebra), but that term originally included the
_Characins_ as well.

[Illustration:

  FIG. 122.—Pharyngeal bones and teeth of European Chub, _Leuciscus
    cephalus_ (Linnæus). (After Seelye.)
]

=The Cyprinidæ.=—The chief family of the _Eventognathi_ and the largest
of all the families of fishes is that of _Cyprinidæ_, comprising 200
genera and over 2000 species, found throughout the north temperate zone
but not extending to the Arctic Circle on the north, nor much beyond the
Tropic of Cancer on the south. In this family belong all the fishes
known as carp, dace, chub, roach, bleak, minnow, bream, and shiner. The
essential character of the family lies in the presence of one, two, or
three rows of highly specialized teeth on the lower pharyngeals, the
main row containing 4, 5, 6, or 7 teeth, the others 1 to 3. The teeth of
the main row differ in form according to the food of the fish. They may
be coarse and blunt, molar-like in those which feed on shells; they may
be hooked at tip in those which eat smaller fishes; they may be serrated
or not; they may have an excavated "grinding surface," which is most
developed in the species which feed on mud and have long intestines. In
the _Cyprinidæ_, or carp family, the barbels are small or wanting, the
head is naked, the caudal fin forked, the mouth is toothless and without
sucking lips, and the premaxillaries form its entire margin. With a few
exceptions the _Cyprinidæ_ are small and feeble fishes. They form most
of the food of the predatory river fishes, and their great abundance in
competition with these is due to their fecundity and their
insignificance. They spawn profusely and find everywhere an abundance of
food. Often they check the increase of predatory fish by the destruction
of their eggs.

In many of the genera the breeding color of the males is very brilliant,
rendering these little creatures for a time the most beautifully colored
of fishes. In spring and early summer the fins, sides, and head in the
males are often charged with pigment, the prevailing color of which is
rosy, though often satin-white, orange, crimson, yellow, greenish, or
jet black. Among American genera _Chrosomus_, _Notropis_, and
_Rhinichthys_ are most highly colored. _Rhodeus_, _Rutilus_, and _Zacco_
in the Old World are also often very brilliant.

[Illustration:

  FIG. 123.—Black-nosed Dace, _Rhinichthys dulcis_ Girard. Yellowstone
    River.
]

In very many species, especially in America, the male in the breeding
season is often more or less covered with small, grayish tubercles or
pearly bodies, outgrowths of the epidermis. These are most numerous on
the head and fall off after the breeding season. They are most developed
in _Campostoma_.

The _Cyprinidæ_ are little valued as food-fishes. The carp, largely
domesticated in small ponds for food, is coarse and tasteless. Most of
the others are flavorless and full of small bones. One species,
_Opsariichthys uncirostris_, of Japan is an exception in this regard,
being a fish of very delicate flavor.

[Illustration:

  FIG. 124.—White Chub, _Notropis hudsonius_ (Clinton). Kilpatrick Lake,
    Minn.
]

[Illustration:

  FIG. 125.—Silver-jaw Minnow, _Ericymba buccata_ Cope. Defiance, Ohio.
]

In America 225 species of _Cyprinidæ_ are known. One hundred of these
are now usually held to form the single genus _Notropis_. This includes
the smaller and weaker species, from two to seven inches in length,
characterized by the loss, mostly through degeneration, of special
peculiarities of mouth, fins, and teeth. These have no barbels and never
more than four teeth in the main row. Few, if any, Asiatic species have
so small a number, and in most of these the maxillary still retains its
rudimentary barbel. But one American genus (_Orthodon_) has more than
five teeth in the main row and none have more than two rows or more than
two teeth in the lower row. By these and other peculiarities it would
seem that the American species are at once less primitive and less
complex than the Old World forms. There is some evidence that the group
is derived from Asia through western America, the Pacific Coast forms
being much nearer the Old World types than the forms inhabiting the
Mississippi Valley. Not many _Cyprinidæ_ are found in Mexico, none in
Cuba, South America, Australia, Africa, or the islands to the eastward
of Borneo. Many species are very widely distributed, many others
extremely local. In the genus _Notropis_, each river basin in the
Southern States has its series of different and mostly highly colored
species. The presence of _Notropis niveus_ in the Neuse, _Notropis
pyrrhomelas_ in the Santee, _Notropis zonistius_ in the Chattahoochee,
_Notropis callistius_, _trichroistius_, and _stigmaturus_ in the
Alabama, _Notropis whipplei_ in the Mississippi, _Notropis galacturus_
in the Tennessee, and _Notropis cercostigma_ in the Sabine forms an
instructive series in this regard. These fishes and the darters
(_Etheostominæ_) are, among American fishes, the groups best suited for
the study of local problems in distribution.

[Illustration:

  FIG. 126.—Silverfin, _Notropis whipplei_ (Girard). White River,
    Indiana. Family _Cyprinidæ_.
]

=Species of Dace and Shiner.=—Noteworthy species in other genera are the
following:

Largest and best known of the species of _Notropis_ is the familiar
shiner or redfin, _Notropis cornutus_, found in almost every brook
throughout the region east of the Missouri River.

_Campostoma anomalum_, the stone-roller, has the very long intestines
six times the length of its body, arranged in fifteen coils around the
air-bladder. This species feeds on mud and spawns in little brooks,
swarming in early spring throughout the Mississippi Valley, and is
notable for its nuptial tubercles and the black and orange fins.

[Illustration:

  FIG. 127.—Stone-roller, _Campostoma anomalum_ (Rafinesque). Family
    _Cyprinidæ_. Showing nuptial tubercles and intestines coiled about
    the air-bladder.
]

In the negro-chub, _Exoglossum maxillingua_ of the Pennsylvanian
district, the rami of the lower jaw are united for their whole length,
looking like a projecting tongue.

[Illustration:

  FIG. 128.—Head of Day-chub, _Exoglossum maxillingua_ (Le Sueur).
    Shenandoah River.
]

The fallfish, _Semotilus corporalis_, is the largest chub of the Eastern
rivers, 18 inches long, living in swift, clear rivers. It is a soft
fish, and according to Thoreau "it tastes like brown paper salted" when
it is cooked. Close to this is the horned dace, _Semotilus
atromaculatus_, and the horny head, _Hybopsis kentuckiensis_, both among
the most widely distributed of our river fishes. These are all allied to
the gudgeon (_Gobio gobio_), a common boys' fish of the rivers of
Europe, and much sought by anglers who can get nothing better. The
bream, _Abramis_, represented by numerous species in Europe, has a deep
compressed body and a very long anal fin. It is also well represented in
America, the golden shiner, common in Eastern and Southern streams,
being _Abramis chrysoleucus_. The bleak of Europe (_Alburnus alburnus_)
is a "shiner" close to some of our species of _Notropis_, while the
minnow of Europe, _Phoxinus phoxinus_, resembles our gorgeously colored
_Chrosomus erythrogaster_. Other European forms are the roach (_Rutilus
rutilus_), the chub (_Leuciscus cephalus_), the dace (_Leuciscus
leuciscus_), the id (_Idus idus_), the redeye (_Scardinius
erythropthalmus_), and the tench (_Tinca tinca_). The tench is the
largest of the European species, and its virtues with those of its more
or less insignificant allies are set forth in the pages of Izaak Walton.
All of these receive more attention from anglers in England than their
relatives receive in America. All the American _Cyprinidæ_ are ranked as
"boys' fish," and those who seek the trout or black bass or even the
perch or crappie will not notice them. Thoreau speaks of the boy who
treasures the yellow perch as a real fish: "So many unquestionable fish
he counts, then so many chubs which he counts, then throws away."

[Illustration:

  FIG. 129.—Horned Dace, _Semotilus atromaculatus_ (Mitchill). Aux
    Plaines River, Ill. Family _Cyprinidæ_.
]

[Illustration:

  FIG. 130.—Shiner, _Abramis chrysoleucus_ (Mitchill). Hackensack River,
    N. J.
]

[Illustration:

  FIG. 131.—The Squawfish, _Ptychocheilus grandis_ Agassiz. (Photograph
    by Cloudsley Rutter.)
]

=Chubs of the Pacific Slope.=—In the Western waters are numerous genera,
some of the species reaching a large size. The species of squawfish
(_Ptychocheilus lucius_ in the Colorado, _Ptychocheilus grandis_ in the
Sacramento, and _Ptychocheilus oregonensis_ in the Columbia) reach a
length of 4 or 5 feet or even more. These fishes are long and slender,
with large toothless mouths and the aspect of a pike.

Allied to these are the "hard tails" (_Gila elegans_ and _Gila robusta_)
of the Colorado Basin, strange-looking fishes scarcely eatable, with
lean bodies, flat heads, and expanded tails. The split-tail,
_Pogonichthys macrolepidotus_, is found in the Sacramento.

[Illustration:

  FIG. 132.—Chub of the Great Basin, _Leuciscus lineatus_ (Girard).
    Heart Lake, Yellowstone Park. Family _Cyprinidæ_.
]

In the chisel-mouth, _Acrocheilus alutaceus_, of the Columbia the lips
have a hard cutting edge. In _Meda_, very small fishes of the Colorado
Basin, the dorsal has a compound spine of peculiar structure. Many of
the species of Western waters belong to the genus _Leuciscus_, which
includes also many species of Asia and Europe. The common Japanese dace
(_Leuciscus hakuensis_) is often found out in the sea, but, in general,
_Cyprinidæ_ are only found in fresh waters. The genus of barbels
(_Barbus_) contains many large species in Europe and Asia. In these the
barbel is better developed than in most other genera, a character which
seems to indicate a primitive organization. _Barbus mosal_ of the
mountains of India is said to reach a length of more than six feet and
to have "scales as large as the palm of the hand."

=The Carp and Goldfish.=—In the American and European _Cyprinidæ_ the
dorsal fin is few-rayed, but in many Asiatic species it is longer,
having 15 to 20 rays and is often preceded by a serrated spine like that
of a catfish. Of the species with long dorsal the one most celebrated is
the carp (_Cyprinus carpio_). This fish is a native of the rivers of
China, where it has been domesticated for centuries. Nearly three
hundred years ago it was brought to northern Europe, where it has
multiplied in domestication and become naturalized in many streams and
ponds. Of late years the cultivation of the carp has attracted much
attention in America. It has been generally satisfactory where the
nature of the fish is understood and where expectations have not been
too high.

The carp is a dull and sluggish fish, preferring shaded, tranquil, and
weedy waters with muddy bottoms. Its food consists of water insects and
other small animals, and vegetable matter, such as the leaves of aquatic
plants. They can be fed on much the same things as pigs and chickens,
and they bear much the same relation to trout and bass that pigs and
chickens do to wild game and game-birds. The carp is a very hardy fish,
grows rapidly, and has immense fecundity, 700,000 eggs having been found
in the ovaries of a single individual. It reaches sometimes a weight of
30 to 40 pounds. As a food-fish the carp cannot be said to hold a high
place. It is tolerated in the absence of better fish.

The carp, either native or in domestication, has many enemies. In
America, catfish, sunfish, and pike prey upon its eggs or its young, as
well as water-snakes, turtles, kingfishes, crayfishes, and many other
creatures which live about our ponds and in sluggish streams. In
domestication numerous varieties of carp have been formed, the
"leather-carp" (Lederkarpfen) being scaleless, others, "mirror-carp"
(Spiegelkarpfen), having rows of large scales only along the lateral
line or the bases of the fins.

Closely allied to the carp is the goldfish (_Carassius auratus_). This
is also a common Chinese fish introduced in domestication into Europe
and America. The golden-yellow color is found only in domesticated
specimens, and is retained by artificial selection. The native goldfish
is olivaceous in color, and where the species has become naturalized (as
in the Potomac River, where it has escaped from fountains in Washington)
it reverts to its natural greenish hue. The same change occurs in the
rivers of Japan. The goldfish is valued solely for its bright colors as
an ornamental fish. It has no beauty of form nor any interesting habits,
and many of our native fishes (_Percidæ_, _Cyprinidæ_) far excel it in
attractiveness as aquarium fishes. Unfortunately they are less hardy.
Many varieties and monstrosities of the goldfish have been produced by
domestication.

[Illustration:

  FIG. 133.—Lower pharyngeal of _Placopharynx duquesnii_ (Le Sueur).
]

=The Catostomidæ.=—The suckers, or _Catostomidæ_, are an offshoot from
the _Cyprinidæ_, differing chiefly in the structure of the mouth and of
the lower pharyngeal bones. The border of the mouth above is formed
mesially by the small premaxillaries and laterally by the maxillaries.
The teeth of the lower pharyngeals are small and very numerous, arranged
in one series like the teeth of a comb. The lips are usually thick and
fleshy, and the dorsal fin is more or less elongate (its rays eleven to
fifty in number), characters which distinguish the suckers from the
American _Cyprinidæ_ generally, but not from those of the Old World.

About sixty species of suckers are known, all of them found in the
rivers of North America except two, which have been recorded on rather
uncertain authority from Siberia and China. Only two or three of the
species extend their range south of the Tropic of Cancer into Mexico or
Central America, and none occur in Cuba nor in any of the neighboring
islands. The majority of the genera are restricted to the region east of
the Rocky Mountains, although species of _Catostomus_, _Chasmistes_,
_Deltistes_, _Xyrauchen_, and _Pantosteus_ are found in abundance in the
Great Basin and the Pacific slope.

[Illustration:

  FIG. 134.—Creekfish or Chub-sucker, _Erimyzon sucetta_ (Lacépède).
    Nipisink Lake, Illinois. Family _Catostomidæ_.
]

In size the suckers range from six inches in length to about three feet.
As food-fishes they are held in low esteem, the flesh of all being
flavorless and excessively full of small bones. Most of them are
sluggish fishes; they inhabit all sorts of streams, lakes, and ponds,
but even when in mountain brooks they gather in the eddies and places of
greatest depth and least current. They feed on insects and small aquatic
animals, and also on mud, taking in their food by suction. They are not
very tenacious of life. Most of the species swarm in the spring in
shallow waters. In the spawning season they migrate up smaller streams
than those otherwise inhabited by them. The large species move from the
large rivers into smaller ones; the small brook species go into smaller
brooks. In some cases the males in spring develop black or red pigment
on the body or fins, and in many cases tubercles similar to those found
in the _Cyprinidæ_ appear on the head, body, and anal and caudal fins.

[Illustration:

  FIG. 135.—Buffalo-fish, _Ictiobus cyprinella_ (Cuv. & Val.). Normal,
    Ill.
]

[Illustration:

  FIG. 136.—Carp-sucker, _Carpiodes cyprinus_ (Le Sueur). Havre de
    Grace.
]

The buffalo-fishes and carp-suckers, constituting the genera _Ictiobus_
and _Carpiodes_, are the largest of the _Catostomidæ_, and bear a
considerable resemblance to the carp. They have the dorsal fin many
rayed and the scales large and coarse. They abound in the large rivers
and lakes between the Rocky Mountains and the Alleghanies, one species
being found in Central America and a species of a closely related genus
(_Myxocyprinus asiaticus_) being reported from eastern Asia. They rarely
ascend the smaller rivers except for the purpose of spawning. Although
so abundant in the Mississippi Valley as to be of importance
commercially, they are very inferior as food-fishes, being coarse and
bony. The genus _Cycleptu_s contains the black-horse, or Missouri
sucker, a peculiar species with a small head, elongate body, and
jet-black coloration, which comes up the smaller rivers tributary to the
Mississippi and Ohio in large numbers in the spring. Most of the other
suckers belong to the genera _Catostomus_ and _Moxostoma_, the latter
with the large-toothed _Placopharynx_ being known, from the red color of
the fins, as red-horse, the former as sucker. Some of the species are
very widely distributed, two of them (_Catostomus commersoni_, _Erimyzon
sucetta_) being found in almost every stream east of the Rocky Mountains
and _Catostomus catostomus_ throughout Canada to the Arctic Sea. The
most peculiar of the suckers in appearance is the harelip sucker
(_Quassilabia lacera_) of the Western rivers. Very singular in form is
the humpback or razor-back sucker of the Colorado, _Xyrauchen cypho_.

[Illustration:

  FIG. 137.—Common Sucker, _Catostomus commersoni_ (Le Sueur). Ecorse,
    Mich.
]

[Illustration:

  FIG. 138.—California Sucker, _Catostomus occidentalis_ Agassiz.
    (Photograph by Cloudsley Rutter.)
]

=Fossil Cyprinidæ.=—Fossil _Cyprinidæ_, closely related to existing
forms, are found in abundance in fresh-water deposits of the Tertiary,
but rarely if ever earlier than the Miocene. _Cyprinus_ _priscus_ occurs
in the Miocene of Germany, perhaps showing that Germany was the original
home of the so-called "German carp," afterwards actually imported to
Germany from China. Some specimens referred to _Barbus_, _Tinca_,
_Rhodeus_, _Aspius_, and _Gobio_ are found in regions now inhabited by
these genera, and many species are referred to the great genus
_Leuciscus_, _Leuciscus œningensis_ from the Miocene of Germany being
perhaps the best known. Several species of _Leuciscus_ or related genera
are found in the Rocky Mountain region. Among these is the recently
described _Leuciscus turneri_.

[Illustration:

  FIG. 139.—Pharyngeal teeth of Oregon Sucker, _Catostomus
    macrocheilus_.
]

Fossil _Catostomidæ_ are very few and chiefly referred to the genus
_Amyzon_, supposed to be allied to _Erimyzon_, but with a longer dorsal.
_Amyzon commune_ and other species are found in the Rocky Mountains,
especially in the Miocene of the South Park in Colorado and the Eocene
of Wyoming. Two or three species of _Catostomus_, known by their skulls,
are found in the Pliocene of Idaho.

[Illustration:

  FIG. 140.—Razor-back Sucker, _Xyrauchen cypho_ (Lockington). Green
    River, Utah.
]

=The Loaches.=—The _Cobitidæ_, or loaches, are small fishes, all less
than a foot in length, inhabiting streams and ponds of Europe and Asia.
In structure they are not very different from minnows, but they are
rather eel-like in form, and the numerous long barbels about the mouth
strongly suggest affinity with the catfishes. The scales are small, the
pharyngeal teeth few, and the air-bladder, as in most small catfishes,
enclosed in a capsule. The loaches are all bottom fishes of dark colors,
tenacious of life, feeding on insects and worms. The species often bury
themselves in mud and sand. They lie quiet on the bottom and move very
quickly when disturbed much after the manner of darters and gobies.
Species of _Cobitis_ and _Misgurnus_ are widely distributed from England
to Japan. _Nemachilus barbatulus_ is the commonest European species.
_Cobitis tænia_ is found, almost unchanged, from England to the streams
of Japan.

Remains of fossil loaches, mostly indistinguishable from _Cobitis_,
occur in the Miocene and more recent rocks.

From ancestors of loaches or other degraded _Cyprinidæ_ we may trace the
descent of the catfishes.

The _Homalopteridæ_ are small loaches in the mountain streams of the
East Indies. They have no air-bladder and the number of pharyngeal teeth
(10 to 16) is greater than in the loaches, carp, or minnows.



                               CHAPTER IX
                     THE NEMATOGNATHI, OR CATFISHES


=THE Nematognathi.=—The _Nematognathi_ (νῆμα, thread; γνάθος, jaw),
known collectively as catfishes, are recognized at once by the fact that
the rudimentary and usually toothless maxillary is developed as the bony
base of a long barbel or feeler. Usually other feelers are found around
the head, suggesting the "smellers" of a cat. The body is never scaly,
being either naked and smooth or else more or less completely mailed
with bony plates which often resemble superficially those of a sturgeon.
Other distinctive characters are found in the skeleton, notably the
absence of the subopercle, but the peculiar development of the maxillary
and its barbel with the absence of scales is always distinctive. The
symplectic is usually absent, and in some the air-bladder is reduced to
a rudiment inclosed in a bony capsule. In almost all cases a stout spine
exists in the front of the dorsal fin and in the front of each pectoral
fin. This spine, made of modified or coalescent soft rays, is often a
strong weapon with serrated edges and capable of inflicting a severe
wound. When the fish is alarmed, it sets this spine by a rotary motion
in its socket joint. It can then be depressed only by breaking it. By a
rotary motion upward and toward the body the spine is again lowered. The
wounds made by this spine are often painful, but this fact is due not to
a specific poison but to the irregular cut and to the slime of the
spine.

In two genera, _Noturus_ and _Schilbeodes_, a poison-gland exists at the
base of the pectoral spine, and the wound gives a sharp pain like the
sting of a hornet and almost exactly like the sting of a scorpion-fish.
Most of the _Nematognathi_ possess a fleshy or adipose fin behind the
dorsal, exactly as in the salmon. In a few cases the adipose fin
develops an anterior spine and occasionally supporting rays.

All the _Nematognathi_ are carnivorous bottom feeders, devouring any
prey they can swallow. Only a few enter the sea, and they occur in the
greatest abundance in the Amazon region. Upward of 1200 species,
arranged in 150 genera, are recorded. They vary greatly in size, from
two inches to six feet in length. All are regarded as food-fishes, but
the species in the sea have very tough and flavorless flesh. Some of the
others are extremely delicate, with finely flavored flesh and a grateful
absence of small bones.

=Families of Nematognathi.=—According to Dr. Eigenmann's scheme of
classification,[11] the most primitive family of Nematognathi is that of
_Diplomystidæ_, characterized by the presence of a well-developed
maxillary, as in other soft-rayed fishes. The single species,
_Diplomystes papillosus_, is found in the waters of Chile.

Footnote 11:

  A Revision of the South American Nematognathi, 1890, p. 7.

Similar to the _Diplomystidæ_ in all other respects is the great central
family of _Siluridæ_, by far the most numerous and important of all the
divisions of _Nematognathi_.

=The Siluridæ.=—This group has the skin naked or imperfectly mailed, the
barbels on the head well developed, the dorsal short, inserted forward,
the adipose fin without spine, and the lower pharyngeals separate. All
the marine catfishes and most of the fresh-water species belong to this
group, and its members, some 700 species, abound in all parts of the
world where catfishes are known—"a bloodthirsty and bullying race of
rangers inhabiting the river bottoms with ever a lance at rest and ready
to do battle with their nearest neighbor."

=The Sea Catfish.=—In the tropical seas are numerous species of
catfishes belonging to _Tachysurus_, _Arius_, _Galeichthys_,
_Felichthys_, and other related genera. These are sleek, silvery fishes
covered with smooth skin, the head usually with a coat of mail, pierced
by a central fontanelle. Some of them reach a considerable size,
swarming in sandy bays. None are valued as food, being always tough and
coarsely flavored. Sea birds, as the pelican, which devour these
catfishes are often destroyed by the sudden erection of the pectoral
spines. None of these are found in Europe or in Japan. Of the very many
American species the gaff-topsail catfish (_Felichthys felis_), noted
for its very high spines, extends farthest north and is one of the very
largest species. This genus has two barbels at the chin. Most others
have four. The commonest sea catfish of the Carolina coast is
_Galeichthys milberti_. In _Tachysurus_ the teeth on the palate are
rounded, in most of the others they are in villiform bands.

[Illustration:

  FIG. 141.—Gaff-topsail Cat, _Felichthys felis_ (L.). Wood's Hole.
]

[Illustration:

  FIG. 142.—Sea Catfish, _Galeichthys milberti_ (Cuv. & Val.).
    Pensacola.
]

In most or all of the sea catfish the eggs, as large as small peas, are
taken into the mouth of the male and there cared for until hatched.

=The Channel Cats.=—In all the rivers of North America east of the Rocky
Mountains are found catfishes in great variety. The channel cats,
_Ictalurus_, known most readily by the forked tails, are the largest in
size and most valued as food. The technical character of the genus is
the backward continuation of the supraoccipital, forming a bony bridge
to the base of the dorsal. The great blue cat, _Ictalurus furcatus_,
abounds throughout the large rivers of the Southern States and reaches a
weight of 150 pounds or more. It is an excellent food and its firm flesh
is readily cut into steaks. In the Great Lakes and northward is a very
similar species, also of large size, which has been called _Ictalurus
lacustris_. Another similar species is the willow cat, _Ictalurus
anguilla_. The white channel-cat, _Ictalurus punctatus_, reaches a much
smaller size and abounds on the ripples in clear swift streams of the
Southwest, such as the Cumberland, the Alabama, and the Gasconade. It is
a very delicate food-fish, with tender white flesh of excellent flavor.

[Illustration:

  FIG. 143.—Channel Catfish, _Ictalurus punctatus_ (Rafinesque).
    Illinois River. Family _Siluridæ_.
]

=Horned Pout.=—The genus _Ameiurus_ includes the smaller brown catfish,
horned pout, or bullhead. The body is more plump and the caudal fin is
usually but not always rounded. The many species are widely diffused,
abounding in brooks, lakes, and ponds. _Ameiurus nebulosus_ is the
best-known species, ranging from New England to Texas, known in the East
as horned pout. It has been successfully introduced into the Sacramento,
where it abounds, as well as its congener, _Ameiurus catus_ (see Fig.
229, Vol. I), the white bullhead, brought with it from the Potomac. The
latter species has a broader head and concave or notched tail. All the
species are good food-fishes. All are extremely tenacious of life, and
all are alike valued by the urchin, for they will bite vigorously at any
sort of bait. All must be handled with care, for the sharp pectoral
spines make an ugly cut, a species of wound from which few boys' hands
in the catfish region are often free.

[Illustration:

  FIG. 144.—Horned pout, _Ameiurus nebulosus_ (Le Sueur). (From life by
    Dr. R. W. Shufeldt.)
]

In the caves about Conestoga River in Lancaster County, Pennsylvania, is
a partly blind catfish, evidently derived from local species outside the
cave. It has been named _Gronias nigrilabris_.

A few species are found in Mexico, one of them, _Ictalurus_
_meridionalis_, as far south as Rio Usamacinta on the boundary of
Guatemala.

Besides these, a large channel-cat of peculiar dentition, known as
_Istlarius balsanus_, abounds in the basin of Rio Balsas. In Mexico all
catfishes are known as Bagre, this species as Bagre de Rio.

The genus _Leptops_ includes the great yellow catfish, or goujon, known
at once by the projecting lower jaw. It is a mottled olive and yellow
fish of repulsive exterior, and it reaches a very great size. It is,
however, a good food-fish.

=The Mad-toms.=—The genera _Noturus_ and _Schilbeodes_ are composed of
diminutive catfishes, having the pectoral spine armed at base, with a
poison sac which renders its sting extremely painful though not
dangerous. The numerous species of this genus, known as "mad-toms" and
"stone cats," live among weeds in brooks and sluggish streams. Most of
them rarely exceed three inches in length, and their varied colors make
them attractive in the aquarium.

[Illustration:

  FIG. 145.—Mad-tom, _Schilbeodes furiosus_ Jordan & Meek. Showing the
    poisoned pectoral spine. Family _Siluridæ_. Neuse River.
]

=The Old World Catfishes.=—In the catfishes of the Old World and their
relatives, the adipose fin is rudimentary or wanting. The chief species
found in Europe is the huge sheatfish, or wels, _Silurus glanis_. This,
next to the sturgeon, is the largest river fish in Europe, weighing 300
to 400 pounds. It is not found in England, France, or Italy, but abounds
in the Danube. It is a lazy fish, hiding in the mud and thus escaping
from nets. It is very voracious, and many stories are told of the
contents of its stomach. A small child swallowed whole is recorded from
Thorn, and there are still more remarkable stories, but not properly
vouched for. The sheatfish is brown in color, naked, sleek, and much
like an American _Ameiurus_ save that its tail is much longer and more
eel-like. Another large catfish, known to the ancients, but only
recently rediscovered by Agassiz and Garman, is _Parasilurus
aristotelis_ of the rivers of Greece. In China and Japan is the very
similar Namazu, or Japanese catfish, _Parasilurus asotus_, often found
in ponds and used as food. Numerous smaller related catfishes, _Porcus_
(_Bagrus_), _Pseudobagrus_, and related genera swarm in the brooks and
ponds of the Orient.

[Illustration:

  FIG. 146.—Electric Catfish, _Torpedo electricus_ (Gmelin). Congo
    River. (After Boulenger.)
]

In the genus _Torpedo_ (_Malapterurus_) the dorsal fin is wanting.
_Torpedo electricus_, the electric catfish of the Nile, is a species of
much interest to anatomists. The shock is like that of a Leyden jar. The
structures concerned are noticed on p. 186, Vol. I. The generic name
_Torpedo_ was applied to the electric catfish before its use for the
electric ray.

In South America a multitude of genera and species cluster around the
genus _Pimelodus_. Some of them have the snout very long and spatulate.
Most of them possess a very long adipose fin. The species are generally
small in size and with smooth skin like the North American catfishes.
Still other species in great numbers are grouped around the genus
_Doras_. In this group the snout projects, bearing the small mouth at
its end, and the lateral line is armed behind with spinous shields. All
but one of the genera belong to the Amazon district, _Synodontis_ being
found in Africa.

Concerning _Doras_, Dr. Günther observes: "These fishes have excited
attention by their habit of traveling during the dry season from a piece
of water about to dry up in quest of a pond of greater capacity. These
journeys are occasionally of such a length that the fish spends whole
nights on the way, and the bands of scaly travelers are sometimes so
large that the Indians who happen to meet them fill many baskets of the
prey thus placed in their hands. The Indians suppose that the fish carry
a supply of water with them, but they have no special organs and can
only do so by closing the gill-openings or by retaining a little water
between the plates of their bodies, as Hancock supposes. The same
naturalist adds that they make regular nests, in which they cover up
their eggs with care and defend them, male and female uniting in this
parental duty until the eggs are hatched. The nest is constructed, at
the beginning of the rainy season, of leaves and is sometimes placed in
a hole scooped out of the beach."

=The Sisoridæ.=—The _Sisoridæ_ are small catfishes found in swift
mountain streams of northern India. In some of the genera
(_Pseudecheneis_) in swift streams a sucking-disk formed of longitudinal
plates of skin is formed on the breast. This enables these fishes to
resist the force of the water. In one genus, _Exostoma_, plates of skin
about the mouth serve the same purpose.

The _Bunocephalidæ_ are South American catfishes with the dorsal fin
undeveloped and the top of the head rough. In _Platystacus_ (_Aspredo_),
the eggs are carried on the belly of the female, which is provided with
spongy tentacles to which the eggs are attached. After the breeding
season the ventral surface becomes again smooth.

=The Plotosidæ.=—The _Plotosidæ_ are naked catfishes, largely marine,
found along the coasts of Asia. In these fishes the second dorsal is
very long. _Plotosus anguillaris_, the sea catfish of Japan, is a small
species striped with yellow and armed with sharp pectoral spines which
render it a very disagreeable object to the fishermen. In sandy bays
like that of Nagasaki it is very abundant. Allied to this is the small
Asiatic family of _Chacidæ_.

=The Chlariidæ.=—The _Chlariidæ_ are eel-like, with a soft skeleton and
a peculiar accessory gill. These abound in the swamps and muddy streams
of India, where some species reach a length of six feet. One species,
_Chlarias magur_, has been brought by the Chinese to Hawaii, where it
flourishes in the same waters as _Ameiurus nebulosus_, brought from the
Potomac and by Chinese carried from San Francisco.

=The Hypophthalmidæ and Pygidiidæ.=—The _Hypophthalmidæ_ have the minute
air-bladder inclosed in a long bony capsule. The eyes are placed very
low and the skin is smooth. The statement that this family lacks the
auditory apparatus is not correct. The few species belong to northern
South America.

[Illustration:

  FIG. 147.—An African Catfish, _Chlarias breviceps_ Boulenger. Congo
    River. Family _Chlariidæ_. (After Boulenger.)
]

Allied to this group is the family _Pygidiidæ_ with a differently formed
bony capsule and no adipose fin. The numerous species are all South
American, mostly of mountain streams of high altitude. Some are very
small. Certain species are said to flee for protection into the
gill-cavity of larger catfishes. Some are reported to enter the urethra
of bathers, causing severe injuries. The resemblance of certain species
to the loaches, or _Cobitidæ_, is very striking. This similarity is due
to the results of similar environment and necessarily parallel habits.
The _Argidæ_ have the capsule of the air-bladder formed in a still
different fashion. The few species are very small, inhabitants of the
streams of the high Andes.

=The Loricariidæ.=—In the family of _Loricariidæ_ the sides and back are
armed with rough bony plates. The small air-bladder is still in a bony
capsule, and the mouth is small with thick fringed lips. The numerous
species are all small fishes of the South American waters, bearing a
strong external resemblance to _Agonidæ_, but wholly different in
anatomy.

=The Callichthyidæ.=—The _Callichthyidæ_ are also small fishes armed
with a bony interlocking coat of mail. They are closely allied to the
_Pygidiidæ_. The body is more robust than in the _Callichthyidæ_ and the
coat of mail is differently formed. The species swarm in the rivers of
northern South America, where with the mailed _Loricariidæ_ they form a
conspicuous part of the fish fauna.

[Illustration:

  FIG. 148.—_Loricaria aurea_ Steindachner, a mailed Catfish from Rio
    Meta, Venezuela. Family _Loricariidæ_. (After Steindachner.)
]

=Fossil Catfishes.=—Fossil catfishes are very few in number. _Siluridæ_,
allied to _Chlarias_, _Bagarius_, _Heterobranchus_, and other
fresh-water forms of India, are found in the late Tertiary rocks of
Sumatra, and catfish spines exist in the Tertiary rocks of the United
States. Vertebræ in the Canadian Oligocene have been referred by Cope to
species of _Ameiurus_ (_A. cancellatus_ and _A. maconnelli_).
_Rhineastes peltatus_ and six other species, perhaps allied to
_Pimelodus_, have been described by Cope from Eocene of Wyoming and
Colorado. _Bucklandium diluvii_ is found in the Eocene London clays, and
several species apparently marine, referred to the neighborhood of
_Tachysurus_ or _Arius_, are found in Eocene rocks of England.

There is no evidence that the group of catfishes has any great
antiquity, or that its members were ever so numerous and varied as at
the present time. The group is evidently derived from scaly ancestors,
and its peculiarities are due to specialization of certain parts and
degeneration of others.

There is not the slightest reason for regarding the catfishes as direct
descendants of the sturgeon or other Ganoid type. They should rather be
looked upon as a degenerate and highly modified offshoot from the
primitive Characins.

=Order Gymnonoti.=—At the end of the series of _Ostariophysans_ we may
place the _Gymnonoti_ (γυμνός, bare; νῶτος, back). This group contains
about thirty species of fishes from the rivers of South America and
Central America. All are eel-like in form, though the skeleton with the
shoulder-girdle suspended from the cranium is quite unlike that of a
true eel. There is no dorsal fin. The vent is at the throat and the anal
is excessively long. The gill-opening is small as in the eel, and as in
most elongate fishes, the ventral fins are undeveloped. The body is
naked or covered with small scales.

Two families are recognized, differing widely in appearance. The
_Electrophoridæ_ constitutes by itself Cope's order of _Glanencheli_
(γλανίς, catfish; ἔγχελυς, eel). This group he regards as intermediate
between the eel-like catfishes (_Chlarias_) and the true eels. It is
naked and eel-shaped, with a short head and projecting lower jaw like
that of the true eel. The single species, _Electrophorus electricus_,
inhabits the rivers of Brazil, reaching a length of six feet, and is the
most powerful of all electric fishes. Its electric organs on the tail
are derived from modified muscular tissue. They are described on p. 170,
Vol. I.

The _Gymnotidæ_ are much smaller in size, with compressed scaly bodies
and the mouth at the end of a long snout. The numerous species are all
fishes without electric organs. _Eigenmannia humboldti_ of the Panama
region is a characteristic species. No fossil _Gymnonoti_ are recorded.



                               CHAPTER X
                  THE SCYPHOPHORI, HAPLOMI, AND XENOMI


=ORDER Scyphophori.=—The _Scyphophori_ (σκύφος, cup; φορέω, to bear)
constitutes a small order which lies apparently between the _Gymnonoti_
and the _Isospondyli_. Boulenger unites it with the _Isospondyli_. The
species, about seventy-five in number, inhabit the rivers of Africa,
where they are important as food-fishes. In all there is a deep cavity
on each side of the cranium covered by a thin bony plate, the
supertemporal bone. There is no symplectic bone, and the subopercle is
very small or concealed. The gill-openings are narrow and there are no
pharyngeal teeth. The air-bladder connects with the ear, but not
apparently in the same way as with the _Ostariophysan_ fishes, to which,
however, the _Scyphophori_ are most nearly related. In all the
_Scyphophori_ the body is oblong, covered with cycloid scales, the head
is naked, there are no barbels, and the small mouth is at the end of a
long snout. All the species possess a peculiar organ on the tail, which
with reference to a similar structure in _Torpedo_ and _Electrophorus_
is held to be a degenerate electric organ. According to Günther, "it is
without electric functions, but evidently representing a transitional
condition from muscular substance to an electric organ. It is an oblong
capsule divided into numerous compartments by vertical transverse septa
and containing a gelatinous substance."

=The Mormyridæ.=—There are two families of _Scyphophori_. The
_Mormyridæ_ have the ordinary fins and tail of fishes and the
_Gymnarchidæ_ are eel-like, with ventrals, anal and caudal wanting.
_Gymnarchus miloticus_ of the Nile reaches a length of six feet, and it
is remarkable as retaining the cellular structure of the air-bladder as
seen in the garpike and bowfin. It doubtless serves as an imperfect
lung.

The best-known genus of _Scyphophori_ is _Mormyrus_. Species of this
genus found in the Nile were worshiped as sacred by the ancient
Egyptians and pictures of _Mormyrus_ are often seen among the emblematic
inscriptions. The Egyptians did not eat the _Mormyrus_ because with two
other fishes it was accused of having devoured a limb from the body of
Osiris, so that Isis was unable to recover it when she gathered the
scattered remains of her husband.

In _Mormyrus_ the bones of the head are covered by skin, the snout is
more or less elongated, and the tail is generally short and
insignificant. One of the most characteristically eccentric species is
_Gnathonemus curvirostris_, lately discovered by Dr. Boulenger from the
Congo. Fossil _Mormyridæ_ are unknown.

[Illustration:

  FIG. 149.—_Gnathonemus curvirostris_ Boulenger. Family _Mormyridæ_.
    Congo River. (After Boulenger.)
]

=The Haplomi.=—In the groups called _Iniomi_ and _Lyopomi_, the
mesocoracoid arch is imperfect or wanting, a condition which in some
cases may be due to the degeneration produced by deep-sea life. In the
eels a similar condition obtains. In the group called _Haplomi_ (ἁπλοός,
simple; ὤμος, shoulder), as in all the groups of fishes yet to be
discussed, this arch is wholly wanting at all stages of development. In
common with the _Isospondyli_ and with soft-rayed fishes in general the
air-bladder has a persistent air-duct, all the fins are without true
spines, the ventral fins are abdominal, and the scales are cycloid. The
group is a transitional one, lying almost equidistant between the
_Isospondyli_ and the _Acanthopterygii_. Gill unites it with the latter
and Woodward with the former. We may regard it for the present as a
distinct order, although no character of high importance separates it
from either. Hay unites the _Haplom_i with the _Synentognathi_ to form
the order of _Mesichthyes_, or transitional fishes, but the affinities
of either with other groups are quite as well marked as their relation
to each other. Boulenger unites the _Iniomi_ with the _Haplomi_, an
arrangement which apparently has merit, for the most primitive and
non-degenerate _Iniomi_, as _Aulopus_ and _Synodus_, lack both
mesocoracoid and orbitosphenoid. These bones are characteristic of the
_Isospondyli_, but are wanting in _Haplomi_.

There is no adipose dorsal in the typical _Haplomi_, the dorsal is
inserted far back, and the head is generally scaly. Most but not all of
the species are of small size, living in fresh or brackish water, and
they are found in almost all warm regions, though scantily represented
in California, Japan, and Polynesia. The four families of typical
_Haplomi_ differ considerably from one another and are easily
distinguished, although obviously related. Several other families are
provisionally added to this group on account of agreement in technical
characters, but their actual relationships are uncertain.

=The Pikes.=—The _Esocidæ_ have the body long and slender and the mouth
large, its bones armed with very strong, sharp teeth of different sizes,
some of them being movable. The upper jaw is not projectile, and its
margin, as in the _Salmonidæ_, is formed by the maxillary. The scales
are small, and the dorsal fin far back and opposite the anal, and the
stomach is without pyloric cæca. There is but a single genus, _Esox_
(_Lucius_ of Rafinesque), with about five or six living species. Four of
these are North American, the other one being found in Europe, Asia, and
North America.

All the pikes are greedy and voracious fishes, very destructive to other
species which may happen to be their neighbors; "mere machines for the
assimilation of other organisms." Thoreau describes the pike as "the
swiftest, wariest, and most ravenous of fishes, which Josselyn calls the
river-wolf. It is a solemn, stately, ruminant fish, lurking under the
shadow of a lily-pad at noon, with still, circumspect, voracious eye;
motionless as a jewel set in water, or moving slowly along to take up
its position; darting from time to time at such unlucky fish or frog or
insect as comes within its range, and swallowing it at one gulp.
Sometimes a striped snake, bound for greener meadows across the stream,
ends its undulatory progress in the same receptacle."

[Illustration:

  FIG. 150.—The Pike, _Esox-lucius_ L. (From life by R. W. Shufeldt.)
]

As food-fishes, all the _Esocidæ_ rank high. Their flesh is white,
fine-grained, disposed in flakes, and of excellent flavor.

The finest of the _Esocidæ_, a species to be compared, as a grand game
fish, with the salmon, is the muskallunge (_Esox masquinongy_).
Technically this species may be known by the fact that its cheeks and
opercles are both naked on the lower half. It may be known also by its
great size and by its color, young and old being spotted with black on a
golden-olive ground.

[Illustration:

  FIG. 151.—Muskallunge, _Esox masquinongy_ Mitchill. Ecorse, Mich.
]

The muskallunge is found only in the Great Lake region, where it
inhabits the deeper waters, except for a short time in the spring, when
it enters the streams to spawn. It often reaches a length of six feet
and a weight of sixty to eighty pounds. It is necessarily somewhat rare,
for no small locality would furnish food for more than one such giant.
It is, says Hallock, "a long, slim, strong, and swift fish, in every way
formed for the life it leads, that of a dauntless marauder."

A second species of muskallunge, _Esox ohiensis_, unspotted but vaguely
cross-barred, occurs sparingly in the Ohio River and the upper
Mississippi Valley. It is especially abundant in Chautauqua Lake.

The pike (_Esox lucius_) is smaller than the muskallunge, and is
technically best distinguished by the fact that the opercles are naked
below, while the cheeks are entirely scaly. The spots and cross-bars in
the pike are whitish or yellowish, and always paler than the olive-gray
ground color. It is the most widely distributed of all fresh-water
fishes, being found from the upper Mississippi Valley, the Great Lakes,
and New England to Alaska and throughout northern Asia and Europe. It
reaches a weight of ten to twenty pounds or more, being a large strong
fish in its way, inferior only to the muskallunge. In England _Esox
lucius_ is known as the pike, while its young are called by the
diminutive term pickerel. In America the name pickerel is usually given
to the smaller species, and sometimes even to _Esox lucius_ itself, the
word being with us a synonym for pike, not a diminutive.

Of the small pike or pickerel we have three species in the eastern
United States. They are greenish in color and banded or reticulated,
rather than spotted, and, in all, the opercles as well as the cheeks are
fully covered with scales. One of these (_Esox reticulatus_) is the
common pickerel of the Eastern States, which reaches a respectable size
and is excellent as food. The others, _Esox americanus_ along the
Atlantic seaboard and _Esox vermiculatus_ in the middle West, seldom
exceed a foot in length and are of no economic importance.

Numerous fossil species are found in the Tertiary of Europe, _Esox
lepidotus_ from the Miocene of Baden being one of the earliest and the
best known; in this species the scales are much larger than in the
recent species. The fossil remains would seem to indicate that the
origin of the family was in southern Europe, although most of the living
species are American.

[Illustration:

  FIG. 152.—Mud-minnow, _Umbra pygmæa_ (De Kay). New Jersey.
]

=The Mud-minnows.=—Close to the pike is the family of _Umbridæ_, or
mud-minnows, which technically differ from the pikes only in the short
snout, small mouth, and weak dentition. The mud-minnows are small,
sluggish, carnivorous fishes living in the mud at the bottom of cold,
clear streams and ponds. They are extremely tenacious of life, though
soon suffocated in warm waters. The barred mud-minnow of the prairies of
the middle West (_Umbra limi_) often remains in dried sloughs and
bog-holes, and has been sometimes plowed up alive. _Umbra pygmæa_, a
striped species, is found in the Eastern States and _Umbra crameri_ in
bogs and brooks along the Danube. This wide break in distribution seems
to indicate a former wide extension of the range of _Umbridæ_, perhaps
coextensive with _Esox_. Fossil _Umbridæ_ are, however, not yet
recognized.

=The Killifishes.=—Most of the recent _Haplomi_ belong to the family of
_Pœciliidæ_ (killifishes, or Cyprinodonts). In this group the small
mouth is extremely protractile, its margin formed by the premaxillaries
alone much as in the spiny-rayed fishes. The teeth are small and of
various forms according to the food. In most of the herbivorous forms
they are incisor-like, serrate, and loosely inserted in the lips. In the
species that eat insects or worms they are more firmly fixed. The head
is scaly, the stomach without cæca, and the intestines are long in the
plant-eating species and short in the others. There are nearly 200
species, very abundant from New England and California southward to
Argentina, and in Asia and Africa also. In regions where rice is
produced, they swarm in the rice swamps and ditches. Some of them enter
the sea, but none of them go far from shore. Some are brilliantly
colored, and in many species the males are quite unlike the females,
being smaller and more showy. The largest species (_Fundulus_,
_Anableps_) rarely reach the length of a foot, while _Heterandria
formosa_, a diminutive inhabitant of the Florida rivers, scarcely
reaches an inch. Some species are oviparous, but in most of the
herbivorous forms, and some of the others, the eggs are hatched within
the body, and the anal in the male is modified into a long sword-shaped
intromittent organ, placed farther forward than the anal in the female.
The young when born closely resemble the parent. Most of the
insectivorous species swim at the surface, moving slowly with the eyes
partly out of water. This habit in the genus _Anableps_ (four-eyed fish,
or _Cuatro ojos_) is associated with an extraordinary structure of the
eye. This organ is prominent and is divided by a horizontal partition
into two parts, the upper, less convex, adopted for sight in the air,
the lower in the water. The few species of _Anableps_ are found in
tropical America. The species of some genera swim near the bottom, but
always in very shallow waters. All are very tenacious of life, and none
have any commercial value although the flesh is good.

[Illustration:

  FIG. 152_a_.—Four-eyed Fish, _Anableps dovii_ Gill. Tehuantepec,
    Mexico.
]

The unique structure of the eye of this curious fish has been carefully
studied by Mr. M. C. Marsh, pathologist of the U. S. Fish Commission,
who furnishes the following notes published by Evermann & Goldsborough:

"The eye is crossed by a bar, like the diameter of a circle, and
parallel with the length of the body. This bar is darker than the other
external portions of the eyeball and has its edges darker still.
Dividing the external aspect of the eye equally, it has its lower edge
on the same level as the back of the fish, which is flat and straight
from snout to dorsal, or nearly the whole length of the fish; so that
when the body of the fish is just submerged the level of the water
reaches to this bar, and the lower half of the eye is in water, the
upper half in the air. Upon dissecting the eyeball from the orbit, it
appears nearly round. A membranous sheath covers the external part and
invests most of the ball. It may be peeled off, when the dark bar on the
external portion of the eye is seen to be upon this membrane, which may
correspond to the conjunctiva. The back portion of the eyeball being cut
off, one lens is found. The lining of the ball consists, in front, of
one black layer, evidently choroid. Behind there is a retinal layer. The
choroid layer turns up anteriorly, making a free edge comparable to an
iris. The free edge is chiefly evident in the lower part of the eye. A
large pupil is left, but is divided by two flaps, continuations of the
choroid coat, projecting from either side and overlapping. There are
properly then two pupils, an upper and lower, separated by a band
consisting of the two flaps, which may probably, by moving upward and
downward, increase or diminish the size of either pupil; an upward
motion of the flaps increasing the lower pupil at the expense of the
other, and vice versa."

This division of the pupil into two parts permits the fish, when
swimming at the surface of the water, as is its usual custom, to see in
the air with the upper portion and in the water with the lower. It is
thus able to see not only such insects as are upon the surface of the
water or flying in the air above, but also any that may be swimming
beneath the surface.

[Illustration:

  FIG. 153.—Round Minnow, _Cyprinodon variegatus_ Lacépède. St. George
    Island, Maryland.
]

According to Mr. E. W. Nelson, "the individuals of this species swim
always at the surface and in little schools arranged in platoons or
abreast. They always swim headed upstream against the current, and feed
upon floating matter which the current brings them. A platoon may be
seen in regular formation breasting the current, either making slight
headway upstream or merely maintaining their station, and on the qui
vive for any suitable food the current may bring. Now and then one may
be seen to dart forward, seize a floating food particle, and then resume
its place in the platoon. And thus they may be observed feeding for long
periods. They are almost invariably found in running water well out in
the stream, or at least where the current is strongest and where
floating matter is most abundant, for it is upon floating matter that
they seem chiefly to depend. They are not known to jump out of the water
to catch insects flying in the air or resting upon vegetation above the
water surface, nor do they seem to feed to any extent upon all small
crustaceans or other portions of the plankton beneath the surface.

[Illustration:

  FIG. 154.—Everglade Minnow, _Jordanella floridæ_ Goode & Bean.
    Everglades of Florida.
]

"When alarmed—and they are wary and very easily frightened—they escape
by skipping or jumping over the water, 2 or 3 feet at a skip. They rise
entirely out of the water, and at a considerable angle, the head
pointing upward. In descending the tail strikes the water first and
apparently by a sculling motion new impetus is acquired for another
leap. This skipping may continue until the school is widely scattered.
When a school has become scattered, and after the cause of their fright
has disappeared, the individuals soon rejoin each other. First two will
join each other and one by one the others will join them until the whole
school is together again. Rarely do they attempt to dive or get beneath
the surface; when they do they have great difficulty in keeping under
and soon come to the surface again."

[Illustration:

  FIG. 155.—Mayfish, _Fundulus majalis_ (L.) (male). Wood's Hole.
]

[Illustration:

  FIG. 156.—Mayfish, _Fundulus majalis_ (female). Wood's Hole.
]

[Illustration:

  FIG. 157.—Top-minnow, _Zygonectes notatus_ (Rafinesque). Eureka
    Springs, Ark.
]

[Illustration:

  FIG. 158.—Death Valley Fish, _Empetrichthys merriami_ Gilbert.
    Amargosa Desert, Cal. Family _Pœciliidæ_. (After Gilbert.)
]

[Illustration:

  FIG. 159.—Sword-tail Minnow, male, _Xiphophorus helleri_ Heckel. The
    anal fin modified as an intromittent organ. Vera Cruz.
]

Of the many genera of _Pœciliidæ_, top-minnows, and killifishes we may
mention the following: _Cyprinodon_ is made up of chubby little fishes
of eastern America with tricuspid, incisor teeth, oviparous and
omnivorous. Very similar to these but smaller are the species of
_Lebias_ in southern Europe. _Jordanella floridæ_ of the Florida
everglades is similar, but with the dorsal fin long and its first ray
enlarged and spine-like. It strongly resembles a young sunfish. Most of
the larger forms belong to _Fundulus_, a genus widely distributed from
Maine to Guatemala and north to Kansas and southern California.
_Fundulus majalis_, the Mayfish of the Atlantic Coast, is the largest of
the genus. _Fundulus heteroclitus_, the killifish, the most abundant.
_Fundulus diaphanus_ inhabits sea and lake indiscriminately. _Fundulus
stellifer_ of the Alabama is beautifully colored, as is _Fundulus
zebrinus_ of the Rio Grande. The genus _Zygonectes_ includes dwarf
species similar to _Fundulus_, and _Adinia_ includes those with short,
deep body. _Goodea atripinnis_ with tricuspid teeth lives in warm
springs in Mexico, and several species of _Goodea_, _Gambusia_,
_Pœcilia_, and other genera inhabit hot springs of Mexico, Central
America, and Africa. The genus _Gambusia_, the top-minnows, includes
numerous species with dwarf males having the anal modified. _Gambusia
affinis_ abounds in all kinds of sluggish water in the southern
lowlands, gutters and even sewers included. It brings forth its brood in
early spring. Viviparous and herbivorous with modified anal fin are the
species of _Pœcilia_, abundant throughout Mexico and southward to
Brazil; _Mollienesia_ very similar, with a banner-like dorsal fin,
showily marked, occurs from Louisiana southward, and _Xiphophorus_, with
a sword-shaped lobe on the caudal, abounds in Mexico; _Characodon_ and
_Goodea_ (see Fig. 53, Vol. I) in Mexico have notched teeth, and
finally, _Heterandria_ contains some of the least of fishes, the
handsomely colored males barely half an inch long.

[Illustration:

  FIG. 160.—_Goodea luitpoldi_ (Steindachner). A viviparous fish from
    Lake Patzcuaro, Mexico. Family _Pœciliidæ_. (After Meek.)
]

In Lake Titicaca in the high Andes is a peculiar genus (_Orestias_)
without ventral fins. Still more peculiar is _Empetrichthys merriami_ of
the desert springs of the hot and rainless Death Valley in California,
similar to _Orestias_, but with enormously enlarged pharyngeals and
pharyngeal teeth, an adaptation to some unknown purpose. Fossil
Cyprinodonts are not rare from the Miocene in southern Europe. The
numerous species are allied to _Lebias_ and _Cyprinodon_, and are
referred to _Prolebias_ and _Pachylebias_. None are American, although
two American extinct genera, _Gephyrura_ and _Proballostomus_, are
probably allied to this group.

=Amblyopsidæ.=—The cavefishes, _Amblyopsidæ_, are the most remarkable of
the haplomous fishes. In this family the vent is placed at the throat.
The form is that of the _Pœciliidæ_, but the mouth is larger and not
protractile. The species are viviparous, the young being born at about
the length of a quarter of an inch.

[Illustration:

  FIG. 161.—Dismal Swamp Fish, _Chologaster cornutus_ Agassiz. Supposed
    ancestor of _Typhlichthys_. Virginia.
]

In the primitive genus _Chologaster_, the fish of the Dismal Swamp, the
eyes are small but normally developed. _Chologaster cornutus_ abounds in
the black waters of the Dismal Swamp of Virginia, thence southward
through swamps and rice-fields to Okefinokee Swamp in northern Florida.
It is a small fish, less than two inches long, striped with black, and
with the habit of a top-minnow. Other species of _Chologaster_,
possessing eyes and color, but provided also with tactile papillæ, are
found in cave springs in Tennessee and southern Illinois.

[Illustration:

  FIG. 162.—Blind Cave-fish, _Typhlichthys subterraneus_ Girard. Mammoth
    Cave, Kentucky.
]

From _Chologaster_ is directly descended the small blindfish
_Typhlichthys subterraneus_ of the caves of the Subcarboniferous
limestone rocks of southern Indiana and southward to northern Alabama.
As in _Chologaster_, the ventral fins are wanting. The eyes, present in
the young, become defective and useless in the adult, when they are
almost hidden by other tissues. The different parts of the eye are all
more or less incomplete, being without function. The structure of the
eye has been described in much detail in several papers by Dr. Carl H.
Eigenmann. As to the cause of the loss of eyesight two chief theories
exist—the Lamarckian theory of the inheritance in the species of the
results of disuse in the individual and the Weissmannian doctrine that
the loss of sight is a result of panmixia or cessation of selection.
This may be extended to cover reversal of selection, as in the depths of
the great caves the fish without eyes would be at some slight advantage.
Dr. Eigenmann inclines to the Lamarckian doctrine, but the evidence
brought forward fails to convince the present writer that results of
individual use or disuse ever become hereditary or that they are ever
incorporated in the characters of a species. In the caves of southern
Missouri is an independent case of similar degradation. _Troglichthys
rosæ_, the blindfish of this region, has the eye in a different phase of
degeneration. It is thought to be separately descended from some other
species of _Chologaster_. Of this species Mr. Garman and Mr. Eigenmann
have given detailed accounts from somewhat different points of view.

Concerning the habits of the blindfish (_Troglichthys rosæ_), Mr. Garman
quotes the following from notes of Miss Ruth Hoppin, of Jasper County,
Missouri: "For about two weeks I have been watching a fish taken from a
well. I gave him considerable water, changed once a day, and kept him in
an uninhabited place subject to as few changes of temperature as
possible. He seems perfectly healthy and as lively as when first taken
from the well. If not capable of long fasts, he must live on small
organisms my eye cannot discern. He is hardly ever still, but moves
about the sides of the vessel constantly, down and up, as if needing the
air. He never swims through the body of the water away from the sides
unless disturbed. Passing the finger over the sides of the vessel under
water I find it slippery. I am careful not to disturb this slimy coating
when the water is changed.... Numerous tests convince me that it is
through the sense of touch, and not through hearing, that the fish is
disturbed; I may scream or strike metal bodies together over him as near
as possible, yet he seems to take no notice whatever. If I strike the
vessel so that the water is set in motion, he darts away from that side
through the mass of water, instead of around in his usual way. If I stir
the water or touch the fish, no matter how lightly, his actions are the
same."

[Illustration:

  FIG. 163.—Blindfish of the Mammoth Cave, _Amblyopsis spelæus_ (De
    Kay). Mammoth Cave, Kentucky.
]

The more famous blindfish of the Mammoth Cave, _Amblyopsis spelæus_,
reaches a length of five inches. It possesses ventral fins. From this
fact we may infer its descent from some extinct genus which, unlike
_Chologaster_, retains these fins. The translucent body, as in the other
blindfishes, is covered with very delicate tactile papillæ, which form a
very delicate organ of touch.

The anomalous position of the vent in _Amblyopsidæ_ occurs again in an
equally singular fish, _Aphredoderus sayanus_, which is found in the
same waters throughout the same region in which _Chologaster_ occurs. It
would seem as if these lowland fishes of the southern swamps were
remains of a once much more extensive fauna.

No fossil allies of _Chologaster_ are known.

=Kneriidæ, etc.=—The members of the order of _Haplomi_, recorded above,
differ widely among themselves in various details of osteology. There
are other families, probably belonging here, which are still more
aberrant. Among these are the _Kneriidæ_, and perhaps the entire series
of forms called _Iniomi_, most of which possess the osteological traits
of the _Haplomi_.

The family of _Kneriidæ_ includes a few very small fishes of the rivers
of Africa.

=The Galaxiidæ.=—The _Galaxiidæ_ are trout-like fishes of the southern
rivers, where they take the place of the trout of the northern zones.
The species lack the adipose fins and have the dorsal inserted well
backward. According to Boulenger these fishes, having no mesocoraoid,
should be placed among the _Haplomi_. Yet their relation to the
_Haplochitonidæ_ is very close and both families may really belong to
the _Isospondyli_. _Galaxias truttaceus_ is the kokopu, or "trout," of
New Zealand. _Galaxias ocellatus_ is the yarra trout of Australia.
Several other species are found in southern Australia, Tasmania,
Patagonia, and the Falkland Islands, and even in South Africa. This very
wide distribution in the rivers remote from each other has given rise to
the suggestion of a former land connection between Australia and
Patagonia. Other similar facts have led some geologists to believe in
the existence of a former great continent called Antarctica, now
submerged except that part which constitutes the present unknown land of
the Antarctic.

As intimated on p. 253, Vol. I, this distribution of _Galaxias_ with
similar anomalies in other groups could not if unsupported by geological
evidence be held to prove the former extension of the Antarctic
continent. Dr. Boulenger[12] has recently shown that _Galaxias_ lives
freely in salt water, a fact sufficient to account for its wide
distribution in the rivers of the southern hemisphere.

Footnote 12:

  Dr. Boulenger (_Nature_, Nov. 27, 1902) has the following note on
  _Galaxias_: "Most text-books and papers discussing geographical
  distribution have made much of the range of a genus of small fishes,
  somewhat resembling trout, the _Galaxias_, commonly described as true
  fresh-water forms, which have long been known from the extreme south
  of South America, New Zealand, Tasmania, and southern Australia. The
  discovery, within the last few years, of a species of the same genus
  in fresh water near Cape Town, whence it had previously been described
  as a loach by F. de Castelnau, has added to the interest, and has been
  adduced as a further argument in support of the former existence of an
  Antarctic continent. In alluding to this discovery when discussing the
  distribution of African fresh-water fishes in the introduction to my
  work 'Les Poissons du Bassin du Congo,' in 1901, I observed that,
  contrary to the prevailing notion, all species of _Galaxias_ are not
  confined to fresh water, and that the fact of some living both in the
  sea and in rivers suffices to explain the curious distribution of the
  genus; pointing out that in all probability these fishes were formerly
  more widely distributed in the seas south of the tropic of Capricorn,
  and that certain species, adapting themselves entirely to fresh-water
  life, have become localized at the distant points where they are now
  known to exist. Although as recently as October last the distinguished
  American ichthyologist D. S. Jordan wrote (_Science_, xiv, p. 20): 'We
  know nothing of the power of _Galaxias_ to survive submergence in salt
  water, if carried in a marine current': it is an established fact,
  ascertained some years ago by F. E. Clarke in New Zealand and by R.
  Vallentin in the Falkland Islands, that _Galaxias attenuatus_ lives
  also in the sea. In New Zealand it periodically descends to the sea,
  where it spawns, from January to March, and returns from March to May.
  In accordance with these marine habits, this species has a much wider
  range than any of the others, being known from Chile, Patagonia,
  Tierra del Fuego, the Falkland Islands, New Zealand, Tasmania, and
  southern Australia.

  "I now wish to draw attention to a communication made by Captain F. W.
  Hutton in the last number of the Transactions of the New Zealand
  Institute (xxxiv, p. 198), 'On a Marine Galaxias from the Auckland
  Islands.' This fish, named _Galaxias bollansi_, was taken out of the
  mouth of a specimen of _Merganser australis_ during the collection
  excursion to the southern islands of New Zealand made in January,
  1901, by His Excellency the Earl of Ranfurly.

  "It is hoped that by giving greater publicity to these discoveries the
  family _Galaxiidæ_ will no longer be included among those strictly
  confined to fresh waters, and that students of the geographical
  distribution of animals will be furnished with a clue to a problem
  that has so often been discussed on insufficient data. As observed by
  Jordan (_l. c._), all anomalies in distribution cease to be such when
  the facts necessary to understand them are at hand.'

  "Of the fresh-water species of _Galaxias_, eight are known from New
  Zealand and the neighboring islands, seven from New South Wales, three
  or four from south Australia, one from west Australia, two from
  Tasmania, seven from South America, from Chile southwards, and one
  from the Cape of Good Hope."

_Neochanna_ is an ally of _Galaxias_ living in burrows in the clay or
mud like a crayfish, often at a distance from water. As in various other
mud-living types, the ventral fins are obsolete.

=Order Xenomi.=—We must place near the _Haplomi_ the singular group of
_Xenomi_ (ξενός, strange; ὤμος, shoulder), regarded by Dr. Gill as a
distinct order. Externally these fish much resemble the mud-minnows,
differing mainly in the very broad pectorals. But the skeleton is thin
and papery, the two coracoids forming a single cartilaginous plate
imperfectly divided. The pectorals are attached directly to this without
the intervention of actinosts, but in the distal third, according to Dr.
Charles H. Gilbert, the coracoid plate begins to break up into a fringe
of narrow cartilaginous strips. These about equal the very large number
(33 to 36) of pectoral rays, the basal part of each ray being slightly
forked to receive the tip of the cartilaginous strip.

[Illustration:

  FIG. 164.—Alaska Blackfish, _Dallia pectoralis_ (Bean). St. Michaels,
    Alaska.
]

"In the deep-sea eels of the order _Heteromi_ there is a somewhat
similar condition of the coracoid elements inasmuch as the hypercoracoid
and hypocoracoid though present are merely membranous elements
surrounded by cartilage and the actinosts are greatly reduced. It seems
probable that we are dealing in the two cases with independent
degeneration of the shoulder-girdle and that the two groups (_Xenomi_
and _Heteromi_) are not really related." (Gilbert.)

Of the single family _Dalliidæ_, one species is known, the Alaska
blackfish, _Dallia pectoralis_.

This animal, formed like a mud-minnow, reaches a length of eight inches
and swarms in the bogs and sphagnum swamps of northwestern Alaska and
westward through Siberia. It is found in countless numbers according to
its discoverer, Mr. L. M. Turner, "wherever there is water enough to wet
the skin of a fish," and wherever it occurs it forms the chief food of
the natives. Its vitality is most extraordinary. Blackfishes will remain
frozen in baskets for weeks and when thawed out are as lively as ever.
Turner gives an account of a frozen individual swallowed by a dog which
escaped in safety after being thawed out by the heat of the dog's
stomach.



                               CHAPTER XI
                     ACANTHOPTERYGII; SYNENTOGNATHI


=ORDER Acanthopterygii, the Spiny-rayed Fishes.=—The most of the
remaining bony fishes constitute a natural group for which the name
_Acanthopterygii_ (ἄκανθα, spine; πτερύξ, πτερόν, fin or wing) may be
used. This name is often written _Actinopteri_, a form equally correct
and more euphonious and convenient. These fishes are characterized, with
numerous exceptions, by the presence of fin spines, by the connection of
the ventral fins with the shoulder-girdle, by the presence in general of
more than one spine in the anterior part of dorsal and anal fins, and as
a rule of one spine and five rays in the ventral fins, and by the
absence in the adult of a duct to the air-bladder. Minor characters are
these: the pectoral fins are inserted high on the shoulder-girdle, the
scales are often ctenoid, and the edge of the upper jaw is formed by the
premaxillary alone, the maxillary being always toothless.

But it is impossible to define or limit the group by any single
character or group of characters. It is connected with the
_Malacopterygii_ through the _Haplomi_ on the one hand by transitional
groups of genera which may lack any one of these characters. On the
other hand, in the extreme forms, each of these distinctive characters
may be lost through degeneration. Thus fin spines, ctenoid scales, and
the homocercal tail are lost in the codfishes, the connection of
ventrals with shoulder-girdle fails in the _Percesoces_, etc., and the
development of the air-duct is subject to all sorts of variations. In
one family even the adipose fin remains through all the changes and
modifications the species have undergone.

The various transitional forms between the _Haplomi_ and the perch-like
fishes have been from time to time regarded as separate orders. Some of
them are more related to the perch, others rather to ancestors of salmon
or pike, while still others are degenerate offshoots, far enough from
either.

On the whole, all these forms, medium, extreme and transitional, may
well be placed in one order, which would include the primitive
flying-fishes and mullets, the degraded globefishes, and the specialized
flounders. As for the most part these are spiny-rayed fishes, Cuvier's
name _Acanthopterygii_, or _Acanthopteri_, will serve us as well as any.
The _Physoclysti_ of Müller, the _Thoracices_ of older authors, and the
_Ctenoidei_ of Agassiz include substantially the same series of forms.
The order _Teleocephali_ of Gill (τελεός, perfect; κεφαλή, head) has
been lately so restricted as to cover nearly the same ground. In Gill's
most recent catalogue of families, the order _Teleocephali_ includes the
_Haplomi_ and rejects the _Hemibranchii_, _Lophobranchii_,
_Plectognathi_, and _Pediculati_, all of these being groups
characterized by sharply defined but comparatively recent characters not
of the highest importance. As originally arranged, the order
_Teleocephali_ included the soft-rayed fishes as well. From it the
_Ostariophysi_ were first detached, and still later the _Isospondyli_
were regarded by Dr. Gill as a separate order.

We may first take up serially as suborders the principal groups which
serve to effect the transition from soft-rayed to spiny-rayed fishes.

=Suborder Synentognathi.=—Among the transitional forms between the
soft-rayed and the spiny-rayed fishes, one of the most important groups
is that known as _Synentognathi_ (σύν, together; ἔν, within; γνάθος,
jaw). These have, in brief, the fins and shoulder-girdle of _Haplomi_,
the ventral fins abdominal, the dorsal and anal without spines. At the
same time, as in the spiny-rayed fishes, the air-bladder is without duct
and the pectoral fins are inserted high on the side of the body. With
these traits are two others which characterize the group as a suborder.
The lower pharyngeal bones are solidly united into one bone and the
lateral line forms a raised ridge along the lower side of the body.
These forms are structurally allied to the pikes (_Haplomi_), on the one
hand, and to the mullets (_Percesoces_), on the other, and this
relationship accords with their general appearance. In this group as in
all the remaining families of fishes, there is no mesocoracoid, and in
very nearly all of these families the duct to the air-bladder disappears
at an early stage of development.

[Illustration:

  FIG. 165.—Needle-fish, _Tylosurus acus_ (Lacépède). New York.
]

=The Garfishes: Belonidæ.=—There are two principal groups or families
among the _Synentognathi_, the _Belonidæ_, with strong jaws and teeth,
and the _Exocœtidæ_, in which these structures are feeble. Much more
important characters appear in the anatomy. In the _Belonidæ_ the third
upper pharyngeal is small, with few teeth, and the maxillary is firmly
soldered to the premaxillary. The vertebræ are provided with
zygapophyses. The species of _Belonidæ_ are known as garfishes, or
needle-fishes. They resemble the garpike in form, but have nothing else
in common. The body is long and slender, covered with small scales.
Sharp, unequal teeth fill the long jaws and the dorsal is opposite the
anal, on the hinder part of the body. These fishes are green in color,
even the bones being often bright green, while the scales on the sides
have a silvery luster. The species are excellent as food, the green
color being associated with nothing deleterious. All are very voracious
and some of the larger species, 5 or 6 feet long, may be dangerous even
to man. Fishermen have been wounded or killed by the thrust of the sharp
snout of a fish springing into the air. The garfishes swim near the
surface of the water and often move with great swiftness, frequently
leaping from the water. The genus _Belone_ is characterized by the
presence of gill-rakers. _Belone belone_ is a small garfish common in
southern Europe. _Belone platura_ occurs in Polynesia. The American
species (_Tylosurus_) lack gill-rakers. _Tylosurus marinus_, the common
garfish of the eastern United States, often ascends the rivers.
_Tylosurus raphidoma_, _Tylosurus fodiator_, _Tylosurus acus_, and other
species are very robust, with short strong jaws. _Athlennes hians_ is a
very large fish with the body strongly compressed, almost ribbon-like.
It is found in the West Indies and across the Isthmus as far as Hawaii.
Many other species, mostly belonging to _Tylosurus_, abound in the warm
seas of all regions. _Tylosurus ferox_ is the long tom of the Australian
markets. _Potamorrhaphis_ with the dorsal fin low is found in Brazilian
rivers. A few fossil species are referred to _Belone_, _Belone flava_
from the lower Eocene being the earliest.

=The Flying-fishes: Exocœtidæ.=—The family of _Exocœtidæ_ includes the
flying-fishes and several related forms more or less intermediate
between these and the garfishes. In these fishes the teeth are small and
nearly equal and the maxillary is separate from the premaxillary. The
third upper pharyngeal is much enlarged and there are no zygapophyses to
the vertebræ.

The skippers (_Scombresox_) have slender bodies, pointed jaws, and, like
the mackerel, a number of detached finlets behind dorsal and anal,
although in other respects they show no affinity to the mackerel. The
common skipper, or saury (_Scombresox saurus_), is found on both shores
of the North Atlantic swimming in large schools at the surface of the
water, frequently leaping for a little distance like the flying-fish.
They are pursued by the mackerel-like fishes, as the tunny or bonito,
and sometimes by porpoises. According to Mr. Couch, the skippers, when
pursued, "mount to the surface in multitudes and crowd on each other as
they press forward. When still more closely pursued, they spring to the
height of several feet, leap over each other in singular confusion, and
again sink beneath. Still further urged, they mount again and rush along
the surface, by repeated starts, for more than one hundred feet, without
once dipping beneath or scarcely seeming to touch the water. At last the
pursuer springs after them, usually across their course, and again they
all disappear together. Amidst such multitudes—for more than twenty
thousand have been judged to be out of the water together—some must fall
a prey to the enemy; but so many hunting in company, it must be long
before the pursuers abandon. From inspection we could scarcely judge the
fish to be capable of such flights, for the fins, though numerous, are
small, and the pectoral far from large, though the angle of their
articulation is well adapted to raise the fish by the direction of their
motions to the surface."

A similar species, _Cololabis saira_, with the snout very much shorter
than in the Atlantic skipper, is the _Samma_ of the fishermen of Japan.

The hard-head (_Chriodorus atherinoides_) has no beak at all and its
tricuspid incisor teeth are fitted to feed on plants. In this genus, as
in the flying-fishes, there are no finlets. The hard-head is an
excellent food-fish abundant about the Florida Keys but not yet seen
elsewhere.

[Illustration:

  FIG. 166.—Saury, _Scombresox saurus_ (L.). Wood's Hole.
]

[Illustration:

  FIG. 167.—Halfbeak, _Hyporhamphus unifasciatus_ (Ranzani). Chesapeake
    Bay.
]

Another group between the gars and the flying-fishes is that of the
halfbeaks, or balaos, _Hemirhamphus_, etc. These are also vegetable
feeders, but with much smaller teeth, and the lower jaw with a
spear-like prolongation to which a bright-red membrane is usually
attached. Of the halfbeaks there are several genera, all of the species
swimming near the surface in schools and sometimes very swiftly. Some of
them leap into the air and sail for a short distance like flying-fishes,
with which group the halfbeaks are connected by easy gradations. The
commonest species along our Atlantic coast is _Hyporhamphus
unifasciatus_; a larger species, _Hemirhamphus brasiliensis_, abounds
about the Florida Keys. _Euleptorhamphus longirostris_, a ribbon-shaped
elongate fish, with long jaw and long pectorals, is taken in the open
sea, both in the Atlantic and Pacific, being common in Hawaii. The
Asiatic genus _Zenarchopterus_ is viviparous, having the anal fin much
modified in the male, forming an intromittent organ, as in the
_Pœciliidæ_. One species occurs in the river mouths in Samoa.

The flying-fishes have both jaws short, and at least the pectoral fins
much enlarged, so that the fish may sail in the air for a longer or
shorter distance.

[Illustration:

  FIG. 168.—Sharp-nosed Flying-fish, _Fodiator acutus_ (Val.). Panama.
]

The smaller species have usually shorter fins and approach more nearly
to the halfbeaks. _Fodiator acutus_, with sharp jaws, and
_Hemiexocœtus_, with a short beak on the lower jaw, are especially
intermediate. The flight of the flying-fishes is described in detail on
p. 157, Vol. I.

The Catalina flying-fish, _Cypselurus californicus_, of the shore of
southern California is perhaps the largest of the known species,
reaching a length of 18 inches. To this genus, _Cypselurus_, having a
long dorsal and short anal, and with ventrals enlarged as well as
pectorals, belong all the species strongest in flight, _Cypselurus
heterurus_ and _furcatus_ of the Atlantic, _Cypselurus simus_ of Hawaii
and _Cypselurus agoo_ in Japan. The very young of most of these species
have a long barbel at the chin which is lost with age.

In the genus _Exonautes_ the base of anal fin is long, as long as that
of the dorsal. The species of this group, also strong in flight, are
widely distributed. Most of the European flying-fishes, as _Exonautes
rondeleti_, _Exonautes speculiger_, and _Exonautes vinciguerræ_, belong
to this group, while those of _Cypselurus_ mostly inhabit the Pacific.
The large Australian species _Exonautes unicolor_, Fig. 226, Vol. I,
belongs to this group. In the restricted genus _Exocœtus_ the ventral
fins are short and not used in flight. _Exocœtus volitans_ (_evolans_)
is a small flying-fish, with short ventral fins not used for flight. It
is perhaps the most widely distributed of all, ranging through almost
all warm seas. _Parexocœtus brachypterus_, still smaller, and with
shorter, grasshopper-like wings, is also very widely distributed. An
excellent account of the flying-fishes of the world has been given by
Dr. C. F. Lütken (1876), the University of Copenhagen, which institution
has received a remarkably fine series from trading-ships returning to
that port. Later accounts have been given by Jordan and Meek, and by
Jordan and Evermann.

[Illustration:

  FIG. 169.—Catalina Flying-fish, _Cypselurus californicus_ (Cooper).
    Santa Barbara.
]

Very few fossil _Exocœtidæ_ are found. Species of _Scombresox_ and
_Hemirhamphus_ are found in the Tertiary, the earliest being
_Hemirhamphus edwardsi_ from the Eocene of Monte Bolca. No fossil
flying-fishes are known, and the genera, _Exocœtus_, _Exonautes_, and
_Cypselurus_ are doubtless all of very recent origin.



                              CHAPTER XII
                       PERCESOCES AND RHEGNOPTERI


=SUBORDER Percesoces.=—In the line of direct ascending transition from
the _Haplomi_ and _Synentognathi_, the pike and flying-fish, towards the
typical perch-like forms, we find a number of families, perch-like in
essential regards but having the ventral fins abdominal.

These types, represented by the mullet, the silverside, and the
barracuda, have been segregated by Cope as an order called _Percesoces_
(Perca, perch; Esox, pike), a name which correctly describes their real
affinities. In these typical forms, mullet, silverside, and barracuda,
the affinities are plain, but in other transitional forms, as the
threadfin and the stickleback, the relationships are less clear. Cope
adds to the series of _Percesoces_ the _Ophiocephalidæ_, which Gill
leaves with the _Anabantidæ_ among the spiny-rayed forms. Boulenger adds
also the sand-lances (_Ammodytidæ_) and the threadfins (_Polynemidæ_),
while Woodward places here the _Crossognathidæ_. In the present work we
define the _Percesoces_ so as to include all spiny-rayed fishes in which
the ventral fins are naturally abdominal, excepting those having a
reduced number of gill-bones, or of actinosts, or other peculiarities of
the shoulder-girdle. The _Ammodytidæ_ have no real affinities with the
_Percesoces_. The _Crossognathidæ_ and other families with abdominal
ventrals and the dorsal spines wholly obsolete may belong with the
_Haplomi_. Boulenger places the _Chiasmodontidæ_, the _Stromateidæ_, and
the _Tetragonuridæ_ among the _Percesoces_, an arrangement of very
doubtful validity. In most of the _Percesoces_ the scales are cycloid,
the spinous dorsal forms a short separate fin, and in all the air-duct
is wanting.

=The Silversides: Atherinidæ.=—The most primitive of living _Percesoces_
constitute the large family of silversides (_Atherinidæ_), known as
"fishes of the King," Pescados del Rey, Pesce Rey, or Peixe Re, wherever
the Spanish or Portuguese languages are spoken. The species are, in
general, small and slender fishes of dry and delicate flesh, feeding on
small animals. The mouth is small, with feeble teeth. There is no
lateral line, the color is translucent green, with usually a broad
lateral band of silver. Sometimes this is wanting, and sometimes it is
replaced by burnished black. Some of the species live in lakes or
rivers, others in bays or arms of the sea, but never at a distance from
the shore or in water of more than a few feet in depth. The larger
species are much valued as food, the smaller ones, equally delicate, are
fried in numbers as "whitebait," but the bones are firmer and more
troublesome than in the smelts and young herring. The species of the
genus _Atherina_, known as "friars," or "brit," are chiefly European,
although some occur in almost all warm or temperate seas. These are
small fishes, with the mouth relatively large and oblique and the scales
rather large and firm. _Atherina hepsetus_ and _A. presbyter_ are common
in Europe, _Atherina stipes_ in the West Indies, _Atherina bleekeri_ in
Japan, and _Atherina insularum_ and _A. lacunosa_ in Polynesia. The
genus _Chirostoma_ contains larger species, with projecting lower jaw,
abounding in the lakes of Mexico. _Chirostoma humboldtianum_ is very
abundant about Mexico City. Like all the other species of this genus it
is remarkably excellent as food, the different species constituting the
famous "Pescados Blancos" of the great lakes of Chapala and Patzcuaro of
the western slope of Mexico. A very unusual circumstance is this: that
numerous very closely related species occupy the same waters and are
taken in the same nets. In zoology, generally, it is an almost universal
rule that very closely related species occupy different geographical
areas, their separation being due to barriers which prevent
interbreeding. But in the lake of Chapala, near Guadalajara, Prof. John
O. Snyder and the present writer, and subsequently Dr. S. E. Meek, found
ten distinct species of _Chirostoma_, all living together, taken in the
same nets and scarcely distinguishable except on careful examination.
Most of these species are very abundant throughout the lake, and all
reach a length of twelve to fifteen inches. These species are
_Chirostoma estor_, _Ch. lucius_, _Ch. sphyræna_, _Ch. ocotlane_, _Ch.
lermæ_, _Ch. chapalæ_, _Ch. grandocule_, _Ch. labarcæ_, _Ch. promelas_,
and _Ch. bartoni_. A similar assemblage of species nearly all different
from these was obtained by Dr. Seth E. Meek in the lake of Patzcuaro,
farther south. In this lake were found _Ch. attenuatum_, _Ch.
patzcuaro_, _Ch. humboldtianum_, _Ch. grandocule_, and _Ch. estor_. The
lake of Zirahuen, near Chapala, contains _Ch. estor_ and _Ch. zirahuen_.

[Illustration:

  FIG. 170.—Pescado blanco, _Chirostoma humboldtianum_ (Val.). Lake
    Chalco, City of Mexico.
]

[Illustration:

  FIG. 171.—Silverside or Brit, _Kirtlandia vagrans_ (Goode & Bean).
    Pensacola.
]

Still another species, _Ch. jordani_, is found about the city of Mexico,
where it is sold baked in corn-husks. Along the coasts of Peru, Chile,
and Argentina is found still another assemblage of fishes of the king,
with very small scales, constituting the genera _Basilichthys_ and
_Gastropterus_ (_Pisciregia_). _Basilichthys microlepidotus_ is the
common Pesca del Rey of Chile. The small silversides, or "brit," of our
Atlantic coast belong to numerous species of _Menidia_, _Menidia notata_
to the northward and _Menidia menidia_ to the southward being most
abundant. _Kirtlandia laciniata_, with ragged scales, is common along
the Virginia coast, and _K. vagrans_ farther south. Another small
species, very slender and very graceful, is the brook silverside
_Labidesthes sicculus_, which swarms in clear streams from Lake Ontario
to Texas. This species, three to four inches long, has the snout
produced and a very bright silvery stripe along the side. Large and
small species of silversides occur in the sea along the California
coast, where they are known familiarly as "blue smelt" or "Peixe Re."
The most important of these and the largest member of the family,
reaching a length of eighteen inches, is _Atherinopsis californiensis_,
an important food-fish throughout California, everywhere wrongly known
as smelt. _Atherinops affinis_ is much like it, but has Y-shaped teeth.
_Iso flos-maris_, called Nami-no-hana, or flower of the surf, is a
shining little fish with belly shape like that of a herring. It lives in
the surf on the coast of Japan. _Melanotænia nigrans_ of Australia
(family _Melanotæniidæ_) has the lateral band jet-black, as has also
_Melaniris balsanus_ of the rivers of southern Mexico. _Atherinosoma
vorax_ of Australia has strong teeth like those of a barracuda.

[Illustration:

  FIG. 172.—Blue Smelt or Pez del Rey, _Atherinopsis californiensis_
    Girard. San Diego.
]

[Illustration:

  FIG. 173.—Flower of the waves, _Iso flos-maxis_, Jordan & Starks.
    Enoshima, Japan.
]

Fossil species of _Atherina_ occur in the Italian Eocene, the best known
being _Atherina macrocephala_. Another species, _Rhamphognathus
paralepoides_, allied to _Menidia_, occurs in the Eocene of Monte Bolca.

=The Mullets: Mugilidæ.=—The mullets (_Mugilidæ_) are more clumsy in
form than the silversides, robust, with broad heads and stouter
fin-spines. The ventral fins are abdominal but well forward, the pelvis
barely touching the clavicle, a condition to be defined as
"subabdominal." The small mouth is armed with very feeble teeth, often
reduced to mere fringes. The stomach is muscular like the gizzard of a
fowl and the species feed largely on the vegetation contained in mud.
There are numerous species, mostly living in shallow bays and estuaries,
but some of them are confined to fresh waters. All are valued as food
and some of them under favorable conditions are especially excellent.

Most of the species belong to the genera _Mugil_, the mullet of all
English-speaking people, although not at all related to the red mullet
or surmullet of the ancient Romans, _Mullus barbatus_.

The mullets are stoutish fish from one to two feet long, with blunt
heads, small mouths almost toothless, large scales, and a general
bluish-silvery color often varied by faint blue stripes. The most
important species is _Mugil cephalus_, the common striped mullet. This
is found throughout southern Europe and from Cape Cod to Brazil, from
Monterey, California, to Chile, and across the Pacific to Hawaii, Japan,
and the Red Sea. Among specimens from all these regions we can detect no
difference.

Professor Goode gives the following account of its habits:

"The large mullets begin to assemble along the Florida coast in schools
in the height of summer, probably preparatory to spawning, and at this
time the eggs commence to mature. In this season they swim at the
surface, and are then pursued by enemies in the water and the air, and
also fall an easy prey to the fishermen. They appear to prefer to swim
against the wind, and school best with a northeast wind. They also run
against the tide. In Florida the spawning season seems to extend from
the middle of November to the middle of January. Some of the fishermen
say that they go on the mud-flats and oyster-beds at the mouth of the
river to deposit their eggs. What becomes of them after this no one
seems to know, but it is probable that they spread themselves over the
whole surface of water-covered country in such a manner as not to be
perceptible to the fisherman, who makes no effort at this time to secure
the spent, lean fish. Many of them probably find their way to the lakes
and others remain wherever they find good feeding-ground, gathering
flesh and recruiting strength for the great strain of the next spawning
season."

Professor Goode informs us that the fishermen recognize "three distinct
periods of schooling and separate runs of mullet. To what extent these
are founded on tradition, or upon the necessity of change in the size of
the mesh of their nets, it is impossible to say. The 'June mullet'
average about five to the pound; the 'fat mullet,' which are taken from
August 20 to October 1, weigh about two pounds; these have, the
fishermen say, a 'roe of fat' on each side as thick as a man's thumb.
The 'roe mullet' weigh about two and a half pounds and are caught in
November and until Christmas. Between the seasons of 'fat mullet' and
'roe mullet' there is an intermission of two or three weeks in the
fishing." Professor Goode hazards the suggestion that "the 'fat mullet'
of September are the breeding fish of November, with roes in an immature
state, the ova not having become fully differentiated."

The mullet feed on the bottom in quiet water, swimming head downward.
The food is sifted over in the mouth, the mud rejected, and the plants,
chiefly microscopic, retained. Mr. Silas Stearns compares a school of
mullets to barnyard fowls feeding together. When a fish finds a rich
spot the others flock about it as chickens do. The pharyngeals form a
sort of filter, stopping the sand and mud, the coarse parts being
ejected through the mouth. Dr. Günther thus describes this apparatus:

"The upper pharyngeals have a rather irregular form: they are slightly
arched, the convexity being directed toward the pharyngeal cavity,
tapering anteriorly and broad posteriorly. They are coated with a thick,
soft membrane, which reaches far beyond the margin of the bone and is
studded all over with minute horny cilia. Each branchial arch is
provided with a series of long gill-rakers, which are laterally bent
downward, each series closely fitting to the sides of the adjoining
arch; they constitute together a sieve admirably adapted to permit a
transit for the water, retaining at the same time every solid substance
in the cavity of the pharynx."

The young mullet feed in schools and often swim with the head at the
surface of the water.

[Illustration:

  FIG. 174.—Striped Mullet, _Mugil cephalus_ (L.). Wood's Hole, Mass.
]

We are not able to distinguish from the common striped mullet of Europe
and America the mullet of Hawaii, the famous Ama-ama, the most valued of
Hawaiian fishes. This species is reared in mullet ponds, made by
extending a stone wall across an arm of the sea. Through openings in the
wall the young mullet enter, and in its protection they grow very fat on
the abundant algæ and other vegetation. They thus become the most
plentiful and most esteemed of the market fishes of Honolulu. The Awa
(_Chanos_) and the Awa-awa (_Elops_) also enter these ponds and are
reared with the mullet, being similarly but less valued. Unfortunately
the kaku, or small barracuda (_Sphyræna helleri_), also enters with
these helpless fishes and destroys many of the smaller individuals.
Another striped species, also very similar to _Mugil cephalus_ in
appearance and value, in fact indistinguishable from the Hawaiian
mullet, abounds in Japan and India.

The white or unstriped mullets are generally smaller, but otherwise
differ little. _Mugil curema_ is the white mullet of tropical America,
ranging occasionally northward, and several other species occur in the
West Indies and the Mediterranean. The genus _Mugil_ has the eye covered
by thick transparent tissue called the adipose eyelid. In _Liza_ the
adipose eyelid is wanting. _Liza capito_, the big-headed mullet of the
Mediterranean, is a well-known species. Most of the mullets of the south
seas belong to the genus _Liza_. _Liza melinoptera_ and _Liza_
_cæruleomaculata_ are common in Samoa. The genus _Querimana_ includes
dwarf-mullets, two or three inches long, known as whirligig-mullets.
These little fishes gather in small schools and swim round and round on
the surface like the whirligig-beetles, or _Gyrinidæ_, their habits
being like those of the young mullets; some young mullets having been,
in fact, described as species of _Querimana_. The genus _Agonostomus_
includes fresh-water mullets of the mountain rivers of the East and West
Indies and Mexico, locally known as trucha, or trout. _Agonostomus
nasutus_ of Mexico is the best-known species.

[Illustration:

  FIG. 175.—Joturo or Bobo, _Joturus pichardi_ Poey. Rio Bayano, Panama.
]

The Joturo, or Bobo, _Joturus pichardi_, is a very large robust and
vigorous mullet which abounds at the foot of waterfalls in the mountain
torrents of Cuba, eastern Mexico, and Central America. It is a good
food-fish, frequently taken about Jalapa, Havana, and on the Isthmus of
Panama. Its lips are very thick and its teeth are broad, serrated,
loosely inserted incisors.

Fossil mullets are few. _Mugil radobojanus_ is the earliest from the
Miocene of Croatia.

=The Barracudas: Sphyrænidæ.=—The _Sphyrænidæ_, or barracudas, differ
from the mullets in the presence of very strong teeth in the bones of
the large mouth. The lateral line is also developed, there is no
gizzard, and there are numerous minor modifications connected with the
food and habits. The species are long, slender swift fishes, powerful in
swimming and voracious to the last degree. Some of the species reach a
length of six feet or more, and these are almost as dangerous to bathers
as sharks would be. The long, knife-like teeth render them very
destructive to nets. The numerous species are placed in the single genus
_Sphyræna_, and some of them are found in all warm seas, where they feed
freely on all smaller fishes, their habits in the sea being much like
those of the pike in the lakes. The flesh is firm, delicate, and
excellent in flavor. In the larger species, especially in the West
Indies, it may be difficult of digestion and sometimes causes serious
illness, or "ichthyosism."

[Illustration:

  FIG. 176.—Barracuda, _Sphyræna barracuda_ Walbaum. Florida.
]

_Sphyræna sphyræna_ is the spet, or sennet, a rather small barracuda
common in southern Europe. _Sphyræna borealis_ of our eastern coast is a
similar but still feebler species rarely exceeding a foot in length.
These and other small species are feeble folk as compared with the great
barracuda (_Sphyræna barracuda_) of the West Indies, a robust savage
fish, also known as picuda or becuna. _Sphyræna commersoni_ of Polynesia
is a similar large species, while numerous lesser ones occur through the
tropical seas. On the California coast _Sphyræna argentea_ is an
excellent food-fish, slenderer than the great barracuda but reaching a
length of five feet.

Several species of fossil barracuda occur in the Italian Eocene,
_Sphyræna bolcensis_ being the earliest.

=Stephanoberycidæ.=—We may append to the _Percesoces_, for want of a
better place, a small family of the deep sea, its affinities at present
unknown. The _Stephanoberycidæ_ have the ventrals I, 5, subabdominal, a
single dorsal without spine, and the scales cycloid, scarcely
imbricated, each with one or two central spines. The mouth is large,
with small teeth, the skull cavernous, as in the berycoids, from which
group the normally formed ventrals abdominal in position would seem to
exclude it. _Stephanoberyx monæ_ and _S. gilli_ are found at the depth
of a mile and a half below the Gulf Stream. Boulenger first placed them
with the _Percesoces_, but more recently suggests their relationship
with the _Haplomi_. Perhaps, as supposed by Gill, they may prove to be
degenerate berycoids in which the ventral fins have lost their normal
connection.

=Crossognathidæ.=—A peculiar primitive group referred by Woodward to the
_Percesoces_ is the family of _Crossognathidæ_ of the Cretaceous period.
As in these fishes there are no fin-spines, they may be perhaps better
placed with the _Haplomi_. The dorsal fin is long, without distinct
spines, and the abdominal ventrals have six to eight rays. The mouth is
small, with feeble teeth, and the body is elongate and compressed.
_Crossognathus sabandianum_ occurs in the Cretaceous of Switzerland and
Germany, _Syllæmus latifrons_ and other species in the Colorado
Cretaceous, and _Syllæmus anglicus_ in England. The _Crossognathidæ_
have probably the lower pharyngeals separate, else they would be placed
among the _Synentognathi_, a group attached by Woodward, not without
reason, to the _Percesoces_.

=Cobitopsidæ.=—Near the _Crossognathidæ_ may be placed the extinct
_Cobitopsidæ_, _Cobitopsis acuta_ being recorded from the Oligocene of
Puy-de-Dôme in France. In this species there is a short dorsal fin of
about seventeen rays, no teeth, and the well-developed ventral fins are
not far in front of the anal. This little fish bears a strong
resemblance to _Ammodytes_, but the affinities of the latter genus are
certainly with the ophidioid fishes, while the real relationship of
_Cobitopsis_ is uncertain.

[Illustration:

  FIG. 177.—_Cobitopsis acuta_ Gervais, restored. Oligocene of
    Puy-de-Dôme. (After Woodward.)
]

=Suborder Rhegnopteri.=—The threadfins (_Polynemidæ_) are allied to the
mullets, but differ from them and from all other fishes in the structure
of the pectoral fin and its basal bones, or actinosts.

[Illustration:

  FIG. 178.—Shoulder-girdle of a Threadfin, _Polydactylus approximans_
    (Lay & Bennett).
]

[Illustration:

  FIG. 179.—Threadfin, _Polydactylus octonemus_ (Girard). Pensacola.
]

The pectoral fin is divided into two parts, the lower composed of free
or separate rays very slender and thread-like, sometimes longer than the
body. Two of the actinosts of the pectoral support the fin, one is
slender and has no rays, while the fourth is plate-like and attached to
the coracoids, supporting the pectoral filaments. The body is rather
robust, covered with large scales, formed much as in the mullet. The
lateral line extends on the caudal fin as in the _Sciænidæ_ which group
these fishes resemble in many ways. The mouth is large, inferior, with
small teeth. The species are carnivorous fishes of excellent flesh,
abounding on sandy shores in the warm seas. They are not very active and
not at all voracious. The coloration is bluish and silvery, sometimes
striped with black. Most of the species belong to the genus
_Polydactylus_. _Polydactylus virginicus_, the barbudo, with seven
filaments, is common in the West Indies and Florida. _Polydactylus
octonemus_ with eight filaments is more rare, but ranges further north.
_Polydactylus approximans_, the raton of western Mexico, with six
filaments, reaches San Diego. _Polydactylus plebejus_ is common in Japan
and other species range through Polynesia. In India isinglass is made
from the large air-bladder of species of _Polydactylus_. The rare
_Polynemus quinquarius_ of the West Indies have five pectoral filaments,
these being greatly elongate, much longer than the body.

No extinct _Polynemidæ_ are recorded.



                              CHAPTER XIII
             PHTHINOBRANCHII: HEMIBRANCHII, LOPHOBRANCHII,
                            AND HYPOSTOMIDES


[Illustration:

  FIG. 180.—Shoulder-girdle of a Stickleback, _Gasterosteus aculeatus_
    Linnæus. (After Parker.)
]

[Illustration:

  FIG. 181.—Shoulder-girdle of _Fistularia petimba_ Lacépède, showing
    greatly extended interclavicle, the surface ossified.
]

=SUBORDER Hemibranchii.=—Still another transitional group, the
_Hemibranchii_, is composed of spiny-rayed fishes with abdominal
ventrals. In this suborder there are other points of divergence, though
none of high importance. In these fishes the bones of the
shoulder-girdle are somewhat distorted, the supraclavicle reduced or
wanting, and the gill structures somewhat degenerate. The presence of
bones called interclavicles or infraclavicles, below and behind the
clavicle, has been supposed to characterize the order of _Hemibranchii_.
But this character has very slight importance. In two families,
_Macrorhamphosidæ_ and _Centriscidæ_, the interclavicles are absent
altogether. In the _Fistulariidæ_ they are very large. According to the
studies of Mr. Edwin C. Starks, the bone in question is not a true
infraclavicle. It is not identical with the infraclavicle of the
Ganoids, but it is only a backward extension of the hypocoracoid, there
being no suture between the two bones. In those species which have bony
plates instead of scales, this bone has a deposit of bony substance or
ganoid enamel at the surface. This gives it an apparent prominence as
compared with other bones of the skeleton, but it has no great taxonomic
importance. Dr. Hay unites the suborders _Hemibranchii_,
_Lophobranchii_, and _Hypostomides_ to form the order _Phthinobranchii_
(φθινάς, waning; βράγχος, gill), characterized by the reduction of the
gill-arches. These forms are really nearly related, but their affinities
with the _Percesoces_ are so close that it may not be necessary to form
a distinct order of the combined group. Boulenger unites the
_Hemibranchii_ with _Lampris_ to form a group, _Catosteomi_,
characterized by the development of infraclavicles; but we cannot see
that _Lampris_ bears any affinity to the sticklebacks, or that the
presence of infraclavicle has any high significance, nor is it the
supposed infraclavicle of _Lampris_ homologous with that of the
_Hemibranchii_. The dorsal fin in the _Hemibranchii_ has more or less
developed spines; spines are also present in the ventral fins. The lower
pharyngeals are separated; there is no air-duct. The mouth is small and
the bones of the snout are often much produced. The preopercle and
symplectic are distinct. The group is doubtless derived from some
transitional spiny-rayed type allied to the _Percesoces_. The
Lophobranchs, another supposed order, represent simply a still further
phase of degradation of gills and ventral fins. Dr. Gill separates these
two groups as distinct orders and places them, as aberrant offshoots,
near the end of his series of bony fishes. We prefer to leave them with
the other transitional forms, not regarding their traits of divergence
as of any great importance in the systematic arrangement of families.

=The Sticklebacks: Gasterosteidæ.=—The sticklebacks (_Gasterosteidæ_)
are small, scaleless fishes, closely related to the _Fistulariidæ_ so
far as anatomy is concerned, but with very different appearance and
habits. The body often mailed, the dorsal is preceded by free spines and
the ventrals are each reduced to a sharp spine with a rudimentary ray.
The jaws are short, bristling with sharp teeth, and these little
creatures are among the most active, voracious, and persistent of all
fishes. They attack the fins of larger fishes, biting off pieces, and at
the same time they devour the eggs of all species accessible to them. In
almost all fresh and brackish waters of the north temperate zone these
little fishes abound. "It is scarcely to be conceived," Dr. Günther
observes, "what damage these little fishes do, and how greatly
detrimental they are to the increase of all the fishes among which they
live, for it is with the utmost industry, sagacity, and greediness that
they seek out and destroy all the young fry that come their way."

The sticklebacks inhabit brackish and fresh waters of the northern
hemisphere, species essentially alike being found throughout northern
Europe, Asia, and America. The same species is subject to great
variation. The degree of development of spines and bony plates is
greatest in individuals living in the sea and least in clear streams of
the interior. Each of the mailed species has its series of half-mailed
or even naked varieties found in the fresh waters. This is true in
Europe, New England, California, and Japan. The farther the individuals
are from the sea, the less perfect is their armature. Thus,
_Gasterosteus cataphractus_, which in the sea has a full armature of
bony plates on the side, about 30 in number, will have in river mouths
from 6 to 20 plates and in strictly fresh water only 2 or 3 or even none
at all.

The sticklebacks have been noted for their nest-building habits. The
male performs this operation, and he is provided with a special gland
for secretion of the necessary cement. Dr. Gill quotes from Dr. John A.
Ryder an account of this process. The secretory gland is a "large
vesicle filled with a clear secretion which coagulates into threads upon
contact with water. It appears to open directly in front of the vent. As
soon as it is ruptured, it loses its transparency, and whatever
secretion escapes becomes whitish after being in contact with water for
a short time. This has the same tough, elastic qualities as when spun by
the animal itself, and is also composed of numerous fibers, as when a
portion is taken that has been recently spun upon the nest. Thus
provided, when the nuptial season has arrived the male stickleback
prepares to build his nest, wherein his mate may deposit her eggs. How
this nest is built, and the subsequent proceedings of the sticklebacks,
have been told us in a graphic manner by Mr. John K. Lord, from
observations on _Gasterosteus cataphractus_ on Vancouver Island,
although the source of his secretion was misunderstood:

"The site is generally amongst the stems of aquatic plants, where the
water always flows but not too swiftly. He first begins by carrying
small bits of green material which he nips off the stalks and tugs from
out the bottom and sides of the bank; these he attaches by some
glutinous material, that he clearly has the power of secreting, to the
different stems destined as pillars for his building. During this
operation he swims against the work already done, splashes about, and
seems to test its durability and strength; rubs himself against the tiny
kind of platform, scrapes the slimy mucus from his sides to mix with and
act as mortar for his vegetable bricks. Then he thrusts his nose into
the sand at the bottom, and, bringing a mouthful, scatters it over the
foundation; this is repeated until enough has been thrown on to weight
the slender fabric down and give it substance and stability. Then more
twists, turns, and splashings to test the firm adherence of all the
materials that are intended to constitute the foundation of the house
that has yet to be erected on it. The nest, or nursery, when completed
is a hollow, somewhat rounded, barrel-shaped structure worked together
much in the same way as the platform fastened to the water-plants; the
whole firmly glued together by the viscous secretion scraped from off
the body. The inside is made as smooth as possible by a kind of
plastering system; the little architect continually goes in, then,
turning round and round, works the mucus from his body on to the inner
sides of the nest, where it hardens like tough varnish. There are two
apertures, smooth and symmetrical as the hole leading into a wren's
nest, and not unlike it.

"All this laborious work is done entirely by the male fish, and when
completed he goes a-wooing. Watch him as he swims towards a group of the
fair sex enjoying themselves amidst the water-plants arrayed in his best
and brightest livery, all smiles and amiability; steadily and in the
most approved style of stickleback love-making this young and wealthy
bachelor approaches the object of his affections, most likely tells her
all about his house and its comforts, hints delicately at his readiness
and ability to defend her children against every enemy, vows unfailing
fidelity, and in lover fashion promises as much in a few minutes as
would take a lifetime to fulfill. Of course she listens to his suit;
personal beauty, indomitable courage, backed by the substantial
recommendations of a house ready built and fitted for immediate
occupation, are gifts not to be lightly regarded.

"Throwing herself on her side the captive lady shows her appreciation,
and by sundry queer contortions declares herself his true and devoted
spouse. Then the twain return to the nest, into which the female at once
betakes herself and therein deposits her eggs, emerging, when the
operation is completed, by the opposite hole. During the time she is in
the nest (about six minutes) the male swims round and round, butts and
rubs his nose against it, and altogether appears to be in a state of
defiant excitement. On the female leaving, he immediately enters,
deposits the milt on the eggs, taking his departure through the back
door. So far his conduct is strictly pure; but I am afraid morality in
stickleback society is of rather a lax order. No sooner has this lady,
his first love, taken her departure, than he at once seeks another,
introduces her as he did the first, and so on, wife after wife, until
the nest is filled with eggs, layer upon layer, milt being carefully
deposited betwixt each stratum of ova. As it is necessary there should
be two holes, by which ingress and egress can be readily accomplished,
so it is equally essential in another point of view. To fertilize
fish-eggs, running water is the first necessity; and, as the holes are
invariably placed in the direction of the current, a steady stream of
water is thus directed over them."

To the genus _Gasterosteus_ the largest species belong, those having
three dorsal spines, and the body typically fully covered with bony
plates. _Gasterosteus aculeatus_ inhabits both shores of the Atlantic
and the scarcely different _Gasterosteus cataphractus_ swarms in the
inlets from southern California to Alaska, Siberia, and northern Japan.
Half-naked forms have been called by various names and one entirely
naked in streams of southern California is named _Gasterosteus
williamsoni_. Its traits are, however, clearly related to its life in
fresh waters.

In _Pygosteus pungitius_, a type of almost equally wide range, there are
nine or ten dorsal spines and the body is more slender. All kinds of
waters of the north on both continents may yield this species or its
allies and variations, mailed or naked. The naked, _Apeltes quadracus_,
is found in the sea only, along the New England coast.

[Illustration:

  FIG. 182.—Three-spined Stickleback, _Gasterosteus aculeatus_ L. Wood's
    Hole, Mass.
]

[Illustration:

  FIG. 183.—Four-spined Stickleback, _Apeltes quadracus_ Mitchill.
    Wood's Hole, Mass.
]

_Eucalia inconstans_ is the stickleback of the clear brook from New York
to Indiana and Minnesota. The male is jet black in spring with the sheen
of burnished copper and he is intensely active in his work of protecting
the eggs of his own species and destroying the eggs and fry of others.
_Spinachia spinachia_ is a large sea stickleback of Europe with many
dorsal spines.

No fossil _Gasterosteidæ_ are recorded, and the family, while the least
specialized in most regards, is certainly not the most primitive of the
suborder.

=The Aulorhynchidæ.=—Closely related to the sticklebacks is the small
family of _Aulorhynchidæ_, with four soft rays in the ventral fins.
_Aulorhynchus_, like _Spinachia_, has many dorsal spines and an elongate
snout approaching that of a trumpet-fish. _Aulorhynchus flavidus_ lives
on the coast of California and _Aulichthys japonicus_ in Japan. The
extinct family of _Protosyngnathidæ_ is near _Aulorhynchus_, with the
snout tubular, the ribs free, not anchylosed as in _Aulorhynchus_, and
with the first vertebræ fused, forming one large one as in _Aulostomus_.
_Protosyngnathus sumatrensis_ occurs in Sumatra. _Protaulopsis
bolcensis_ of the Eocene of Italy has the ventral fins farther back, and
is probably more primitive than the sticklebacks.

=Cornet-fishes: Fistulariidæ.=—Closely related to the sticklebacks so
far as structure is concerned is a family of very different habit, the
cornet-fishes, or cornetas (_Fistulariidæ_). In these fishes the body is
very long and slender, like that of a garfish. The snout is produced
into a very long tube, which bears the short jaws at the end. The teeth
are very small. There are no scales, but bony plates are sunk in the
skin. The ventrals are abdominal, each with a spine and four rays. The
four anterior vertebræ are very much elongate. There are no spines in
the dorsal and the back-bone extends through the forked caudal, ending
in a long filament. The cornet-fishes are dull red or dull green in
color. They reach a length of two or three feet, and the four or five
known species are widely distributed through the warm seas, where they
swim in shallow water near the surface. _Fistularia tabaccaria_, the
tobacco-pipe fish, is common in the West Indies, _Fistularia petimba_,
_F. serrata_, and others in the Pacific. A fossil cornet-fish of very
small size, _Fistularia longirostris_, is known from the Eocene of Monte
Bolca, near Verona. _Fistularia kœnigi_ is recorded from the Oligocene
of Glarus.

=The Trumpet-fishes: Aulostomidæ.=—The _Aulostomidæ_, or trumpet-fishes
are in structure entirely similar to the _Fistulariidæ_, but the body is
band-shaped, compressed, and scaly, the long snout bearing the feeble
jaws at the end. There are numerous dorsal spines and no filament on the
tail. _Aulostomus chinensis_ (_maculatus_) is common in the West Indies,
_Aulostomus valentini_ abounds in Polynesia and Asia, where it is a
food-fish of moderate importance. A species of _Aulostomus_
(_bolcensis_) is found in the Italian Eocene. Allied to it is the
extinct family _Urosphenidæ_, scaleless, but otherwise similar.
_Urosphen dubia_ occurs in the Eocene at Monte Bolca. _Urosphen_ is
perhaps the most primitive genus of the whole suborder of
_Hemibranchii_.

[Illustration:

  FIG. 184.—Trumpet-fish, _Aulostomus chinensis_ (L.) Virginia.
]

=The Snipefishes: Macrorhamphosidæ.=—Very remarkable fishes are the
snipefishes, or _Macrorhamphosidæ_. In these forms the snout is still
tubular, with the short jaws at the end. The body is short and deep,
partly covered with bony plates. The dorsal has a very long serrated
spine, besides several shorter ones, and the ventral fins have one spine
and five rays.

[Illustration:

  FIG. 185.—Japanese Snipefish, _Macrorhamphosus sagifue_ Jordan &
    Starks. Misaki, Japan.
]

The snipefish, or woodcock-fish, _Macrorhamphosus scolopax_, is rather
common on the coasts of Europe, and a very similar species (_M.
sagifue_) occurs in Japan. The _Rhamphosidæ_, represented by
_Rhamphosus_, an extinct genus with the ventrals further forward, are
found in the Eocene rocks of Monte Bolca. _Rhamphosus vastrum_ has
minute scales, short dorsal, and the snout greatly attenuate.

=The Shrimp-fishes: Centriscidæ.=—One of the most extraordinary types of
fishes is the small family of _Centriscidæ_, found in the East Indies.
The back is covered by a transparent bony cuirass which extends far
beyond the short tail, on which the two dorsal fins are crowded.
Anteriorly this cuirass is composed of plates which are soldered to the
ribs. The small toothless mouth is at the end of a long snout.

[Illustration:

  FIG. 186.—Shrimp-fish, _Æoliscus strigatus_ (Günther). Riu Kiu
    Islands, Japan.
]

These little fishes with the transparent carapace look very much like
shrimps. _Centriscus scutatus_ (_Amphisile_) with the terminal spine
fixed is found in the East Indies, and _Æoliscus strigatus_ with the
terminal spine movable is found in southern Japan and southwards.

[Illustration:

  FIG. 187.—_Æoliscus heinrichi_ Heckel. Eocene of Carpathia. Family
    _Centriscidæ_. (After Heckel.)
]

A fossil species, _Æoliscus heinrichi_, is found in the Oligocene of
various parts of Europe, and _Centriscus longirostris_ occurs in the
Eocene of Monte Bolca.

In the _Centriscidæ_ and _Macrorhamphosidæ_ the expansions of the
hypocoracoid called infraclavicles are not developed.

=The Lophobranchs.=—The suborder _Lophobranchii_ (λοφός, tuft; βραγχός,
gill) is certainly an offshoot from the _Hemibranchii_ and belongs
likewise among the forms transitional from soft to spiny-rayed fishes.
At the same time it is a degenerate group, and in its modifications it
turns directly away from the general line of specialization.

The chief characters are found in the reduction of the gills to small
lobate tufts attached to rudimentary gill-arches. The so-called
infraclavicles are present, as in most of the _Hemibranchii_. Bony
plates united to form rings take the place of scales. The long tubular
snout bears the short toothless jaws at the end. The preopercle is
absent, and the ventrals are seven-rayed or wanting. The species known
as pipefishes and sea-horses are all very small and none have any
economic value. They are numerous in all warm seas, mostly living in
shallow bays among seaweed and eel-grass. The muscular system is little
developed and all the species have the curious habit of carrying the
eggs until hatched in a pouch of skin under the belly or tail; this
structure is usually found in the male.

=The Solenostomidæ.=—The _Solenostomidæ_ of the East Indies are the most
primitive of these fishes. They have the body rather short and provided
with spinous dorsal, and ventral fins. The pretty species are
occasionally swept northward to Japan in the Black Current.
_Solenostomus cyanopterus_ is a characteristic species. _Solenorhynchus
elegans_, now extinct (with the trunk more elongate), preceded
_Solenostomus_ in the Eocene of Monte Bolca.

=The Pipefishes: Syngnathidæ.=—The _Syngnathidæ_ are very long and
slender fishes, with neither spinous dorsal, nor ventral fins, the body
covered by bony rings. Of the pipefish, _Syngnathus_, there are very
many species on all northern coasts. _Syngnathus acus_ is common in
Europe, _Syngnathus fuscum_ along the New England coast, _Syngnathus
californiense_ in California, and _Syngnathus schlegeli_ in Japan.
Numerous other species of _Syngnathus_ and other genera are found
further south in the same regions. _Corythroichthys_ is characteristic
of coral reefs and _Microphis_ of the streams of the islands of
Polynesia. In general, the more northerly species have the greater
number of vertebræ and of bony rings. _Tiphle tiphle_ is a large
pipefish of the Mediterranean. This species was preceded by _Tiphle
albyi_ (_Siphonostoma_) in the Miocene of Sicily. Other pipefishes,
referred to as _Syngnathus_ and _Calamostoma_, are found as fossils in
Tertiary rocks.

=The Sea-horses: Hippocampus.=—Both fossil and recent forms constitute a
direct line of connection from the pipefishes to the sea-horses. In the
latter the head has the form of the head of a horse. It is bent at right
angles to the body like the head of a knight at chess. There is no
caudal fin, and the tail in typical species is coiled and can hardly be
straightened out. _Calamostoma_ of the Eocene, _Gasterotokeus_ of
Polynesia, and _Acentronura_ of Japan are forms which connect the true
sea-horses with the pipefish. _Gasterotokeus_ has the long head and
slender body of the pipefish, with the prehensile finless tail of a
sea-horse. Most of the living species of the sea-horse belong to the
genus _Hippocampus_. These little creatures have the egg-sac of the male
under the abdomen. They range from two inches to a foot in length and
some of the many species may be found in abundance in every warm sea.
Some cling by the tails to floating seaweed and are swept to great
distances; others cling to eel-grass and live very near the shore. The
commonest European species is _Hippocampus hippocampus_. Most abundant
on our Atlantic coast is _Hippocampus hudsonius_. _Hippocampus
coronatus_ is most common in Japan. The largest species are _Hippocampus
ingens_ of Lower California and _Hippocampus kelloggi_ in Japan. Many
species, especially of the smaller ones, have the spines of the bony
plates of the body ending in fleshy flaps. These are sometimes so
enlarged as to simulate leaves of seaweed, thus serving for the
efficient protection of the species. These flaps are developed to an
extreme degree in _Phyllopteryx eques_, a pipefish of the East Indies.

[Illustration:

  FIG. 188.—_Solenostomus cyanopterus_ Bleeker. Misaki, Japan.
]

[Illustration:

  FIG. 189.—Sea-horse, _Hippocampus hudsonius_ Dekay. Virginia.
]

No fossil sea-horses are known.

The following account of the breeding-habits of our smallest sea-horse
(_Hippocampus zosteræ_) was prepared by the writer for a book of
children's stories:

"He was a little bit of a sea-horse and his name was Hippocampus. He was
not more than an inch long, and he had a red stripe on the fin on his
back, and his head was made of bone and it had a shape just like a
horse's head, but he ran out to a point at his tail, and his head and
his tail were all covered with bone. He lived in the Grand Lagoon at
Pensacola in Florida, where the water is shallow and warm and there are
lots of seaweeds. So he wound his tail around a stem of seaweed and hung
with his head down, waiting to see what would happen next, and then he
saw another little sea-horse hanging on another seaweed. And the other
sea-horse put out a lot of little eggs, and the little eggs all lay on
the bottom of the sea at the foot of the seaweed. So Hippocampus crawled
down from the seaweed where he was and gathered up all those little
eggs, and down on the under side of his tail where the skin is soft he
made a long slit for a pocket, and then he stuffed all the eggs into
this pocket and fastened it together and stuck it with some slime. So he
had all the other sea-horse's eggs in his own pocket.

"Then he went up on the seawrack again and twisted his tail around it,
and hung there with his head down to see what would happen next. The sun
shone down on him, and by and by all the little eggs began to hatch out,
and each one of the eggs was a little sea-pony, shaped just like a
sea-horse. And when he hung there with his head down he could feel all
the little sea-ponies squirming inside his pocket, and by and by they
squirmed so much that they pushed the pocket open, and then every one
crawled away from him, and he couldn't get them back, and so he went
along with them and watched to see that nothing should hurt them. And by
and by they hung themselves all up on the seaweeds, and they are hanging
there yet. And so he crawled back to his own piece of seaweed and
twisted his tail around it, and waited to see what would happen next.
And what happened next was just the same thing over again."

=Suborder Hypostomides, the Sea-moths: Pegasidæ.=—The small suborder of
_Hypostomides_ (ὑπό, below; στόμα, mouth) consists of the family of
_Pegasidæ_. These "sea-moths" are fantastic little fishes, probably
allied to the sticklebacks, but wholly unique in form. The slender body
is covered with bony plates, the gill-covers are reduced to a single
plate. The small mouth underneath a long snout has no teeth. The
preopercle and the symplectic are both wanting. The ventrals are
abdominal, formed of two rays, and the very large pectoral fin is placed
horizontally like a great wing.

[Illustration:

  FIG 190.—Sea-moth, _Zalises umitengu_ Jordan & Snyder. Misaki, Japan.
    (View from below.)
]

The species, few in number, known as sea-moths and sea-dragons, rarely
exceed four inches in length. They are found in the East Indies and
drift with the currents northward to Japan. The genera are _Pegasus_,
_Parapegasus_, and _Zalises_. The best-known species are _Zalises
draconis_ and _Pegasus volitans_.

No fossil species of _Pegasidæ_ are known.



                              CHAPTER XIV
                   SALMOPERCÆ AND OTHER TRANSITIONAL
                                 GROUPS


=SUBORDER Salmopercæ, the Trout-perches: Percopsidæ.=—More ancient than
the _Hemibranchii_, and still more distinctly in the line of transition
from soft-rayed to spiny-rayed fishes, is the small suborder of
_Salmopercæ_. This is characterized by the presence of the adipose fin
of the salmon, in connection with the mouth, scales, and fin-spines of a
perch. The premaxillary forms the entire edge of the upper jaw, the
maxillary being without teeth. The air-bladder retains a rudimentary
duct. The bones of the head are full of mucous cavities, as in the
European perch called _Gymnocephalus_ and _Acerina_. There are two
spines in the dorsal and one or two in the anal, while the abdominal
ventrals have each a spine and eight rays. Two species only are known
among living fishes, these emphasizing more perfectly than any other
known forms the close relation really existing between spinous and
soft-rayed forms. The single family of _Percopsidæ_ would seem to find
its place in Cretaceous rocks rather than in the waters of to-day.

[Illustration:

  FIG. 191.—Sand-roller, _Pecropsis guttatus_ Agassiz. Okoboji Lake, Ia.
]

_Percopsis guttata_, the trout-perch or sand-roller of the Great Lakes,
is a pale translucent fish with dark spots, reaching a length of six
inches. It abounds in the Great Lakes and their tributaries and is
occasionally found in the Delaware, Ohio, Kansas, and other rivers and
northwestward as far as Medicine Hat on the Saskatchewan. It is easily
taken with a hook from the piers at Chicago.

[Illustration:

  FIG. 192.—Oregon Trout-perch, _Columbia transmontana_ Eigenmann.
    Umatilla River, Oregon.
]

_Columbia transmontana_ is another little fish of similar type, but
rougher and more distinctly perch-like. It is found in sandy or weedy
lagoons throughout the lower basin of the Columbia, where it was first
noticed by Dr. Eigenmann in 1892. From the point of view of structure
and classification, this left-over form is one of the most remarkable of
American fishes.

[Illustration:

  FIG. 193.—_Erismatopterus endlicheri_ Cope. Green River Eocene. (After
    Cope.)
]

=Erismatopteridæ.=—Here should perhaps be placed the family of
_Erismatopteridæ_, represented by _Erismatopterus levatus_ and other
species of the Green River Eocene shales. In _Erismatopterus_ the short
dorsal has two or three spines, there are two or three spines in the
anal, and the abdominal ventrals are opposite the dorsal. Allied to
_Erismatopterus_ is _Amphiplaga_ of the same deposits.

We cannot, however, feel sure that these extinct fragments, however well
preserved, belonged to fishes having an adipose fin. Among spiny-rayed
fishes the _Percopsidæ_ alone retain this character, and the real
affinities of _Erismatopterus_ may be with _Aphredoderidæ_ and other
percoid forms.

The relations of the extinct family of _Asineopidæ_ are also still
uncertain. This group comprises fresh-water fishes said to be allied to
the _Aphredoderidæ_, but with the pelvic bones not forked. _Asineops
pauciradiata_, _squamifrons_ and _viridensis_ are described from the
Green River shales. With _Erismatopterus_ all these fishes may belong to
the suborder of _Salmopercæ_, but, as above stated, the possession of
the adipose fin, the most characteristic trait of the _Salmopercæ_,
cannot be verified in the fossil remains.

[Illustration:

  FIG. 194.—Shoulder-girdle of the Opah, _Lampris guttatus_ (Brünnich),
    showing the enlarged infraclavicle. (After Boulenger.)
]

=Suborder Selenichthyes, the Opahs: Lamprididæ.=—We may bring together
as constituting another suborder certain forms of uncertain
relationship, but which seem to be transitional between deep-bodied
extinct Ganoids and the forms allied to _Platax_, _Zeus_, and
_Antigonia_. The name of _Selenichthyes_ (σηλήνη, moon; ἰχθύς, fish) is
suggested by Boulenger for the group of opahs, or moonfishes. These are
characterized by the highly compressed body, the great development of a
large hypocoracoid, and especially by the structure of the ventral fins,
which are composed of about fifteen rays instead of the one spine and
five rays characteristic of the specialized perch-like fishes. The
living forms of this type are further characterized by the partial or
total absence of the spinous dorsal, by the small oblique mouth, and the
prominence of the ventral curve of the body. A thorough study of the
osteology of these forms living and fossil will be necessary before the
group can be properly defined. The large bone above mentioned was at
first considered by Boulenger as the interclavicle or infraclavicle, the
hypocoracoid being regarded by him as displaced, lying with the
actinosts. But it is certain, from the studies of Mr. Starks, that this
bone is the real hypocoracoid, which in this case is simply exaggerated
in size, but placed as in ordinary fishes.

The single living family, _Lamprididæ_, contains but one species,
_Lampris guttatus_, known as opah, moonfish, mariposa, cravo, Jerusalem
haddock, or San Pedro fish. This species reaches a length of six feet
and a weight of 500 to 600 pounds. Fig. 199 (Vol. I) is taken from a
photograph of an example weighing 317½ pounds taken near Honolulu by Mr.
E. L. Berndt. The body is almost as deep as long, plump and smooth,
without scales or bony plates. The vertebræ are forty-five in number,
and the large ventrals contain about fifteen rays. The dorsal is without
spines, the small mouth without teeth. The color is a "rich brocade of
silver and lilac, rosy on the belly, everywhere with round silvery
spots." The head and back have ultramarine tints, the jaws and fins are
vermilion. On a drawing of this fish made at Sable Island in 1856, Mr.
James Farquhar wrote (to Dr. J. Bernard Gilpin): "Just imagine the body,
a beautiful silver interspersed with spots of a lighter color about the
size of sixpence, the eyes very large and brilliant, with a golden ring
around them. You will then have some idea of the splendid appearance of
the fish when fresh. If Caligula had seen them I might have realized a
fortune."

The skeleton of the opah is very firm and heavy. The flesh is of varying
shades of salmon-red, tender, oily, and of a rich, exquisite flavor
scarcely surpassed by any other fish whatsoever.

The opah is a rare fish, swimming slowly near the surface and ranging
very widely in all the warm seas. It was first noticed in Norway by
Gunner, the good bishop of Throndhjem, about 1780. It was soon after
recorded from Elsinore, Torbay, and Madeira, and is occasionally taken
in various places in Europe. It is also recorded from Newfoundland,
Sable Island, Cuba, Monterey, San Pedro Point (near San Francisco),
Santa Catalina, Honolulu, and Japan.

The specimen studied by the writer came ashore at Monterey in an injured
condition, having been worsted in a struggle with some better-armed
fish.

Allied to _Lampris_ is the imposing extinct species known as
_Semiophorus velifer_ from the Eocene of Monte Bolca near Verona, the
type of the extinct family of _Semiophoridæ_. This is a deep compressed
fish, with very high spinous dorsal and very long, many-rayed ventrals.
Other related species are known also from the Eocene. There is no
evidence of any close relation between these fishes with _Caranx_ or
_Platax_, with which Woodward associates _Semiophorus_.

The _Semiophoridæ_ differ from the _Lamprididæ_ chiefly in the
development of the spinous dorsal fin, which is composed of many slender
rays.

=Suborder Zeoidea.=—Not far from the _Selenichthyes_ and the
_Berycoidei_ we may place the singular group of John Dories, or zeoid
fishes. These have the ventral fins thoracic and many-rayed, the dorsal
fin provided with spines, and the post-temporal, as in the
_Chætodontidæ_, fused with the skull. Dr. Boulenger calls attention to
the close relation of these fishes to the flounders, and suggests the
possible derivation of both from a synthetic type, the _Amphistiidæ_,
found in the European Eocene. The _Amphistiidæ_, _Zeidæ_, and flounders
are united by him to form the group or suborder _Zeorhombi_,
characterized by the thoracic ventrals, which have the rays not I, 5 in
number, by the progressive degeneration of the fin-spines and the
progressive twisting of the cranium, bringing the two eyes to the same
side of the head. It is not certain that the flounders are really
derived from Zeus-like fishes, but no other guess as to their origin has
more elements of probability.

[Illustration:

  FIG. 195.—_Semiophorus velifer_ Volta. Eocene. (After Agassiz, per
    Zittel.)
]

We may, however, regard the _Zeoidea_ on the one hand and the
_Heterosomata_ on the other as distinct suborders. This is certain, that
the flounders are descended from spiny-rayed forms and that they have no
affinities with the codfishes.

[Illustration:

  FIG. 196.—_Amphistium paradoxum_ Agassiz. Upper Eocene. (Supposed
    ancestor of the flounders). (After Boulenger.)
]

=Amphistiidæ.=—The _Amphistiidæ_, now extinct, are deep-bodied,
compressed fishes, with long, continuous dorsal and anal fins in which a
few of the anterior rays are simple, slender spines scarcely
differentiated from the soft rays. The form of body and the structure of
the fins are essentially as in the flounders, from which they differ
chiefly by the symmetry of the head, the eyes being normally placed.
_Amphistium paradoxum_ is described by Agassiz from the upper Eocene. It
occurs in Italy and France. In its dorsal and anal fins there are about
twenty-two rays, the first three or four undivided. The teeth are minute
or absent and there is a high supraoccipital crest.

=The John Dories: Zeidæ.=—The singular family of _Zeidæ_, or John
Dories, agrees with Chætodonts in the single character of the fusion of
the post-temporal with the skull. The species, however, diverge widely
in other regards, and their ventral fins are essentially those of the
Berycoids. In all the species there are seven to nine soft rays in the
ventral fins, as in the Berycoid fishes. Probably the character of the
fused post-temporal has been independently derived. The anterior
vertebræ in _Zeus_, as in _Chætodon_, are closely crowded together. In
the _Zeidæ_ the spinous dorsal is well developed, the body naked or with
very thin scales, and provided with bony warts at least around the bases
of dorsal and anal fins. The species are mostly of small size, silvery
in color, living in moderate depths in warm seas. The best-known genus
is _Zeus_, which is a group of shore-fishes of the waters of Asia and
Europe. The common John Dory (called in Germany Härings-König, or king
of the herrings), _Zeus faber_, abounds in shallow bays on the coasts of
Europe. It reaches a length of nearly a foot, and is a striking feature
of the markets of southern Europe. The dorsal spines are high, the mouth
large, and on the sides is a black ring, said by some to be the mark of
the thumb of St. Peter, who is reported to have taken a coin from the
mouth of this species. A black spot on several other species is
associated with the same legend.

[Illustration:

  FIG. 197.—The John Dory, _Zeus faber_. Linnæus. Devon, England.
]

On the coasts of Japan abounds the Matao, or target-fish (_Zeus
japonicus_), very similar to the European species and like it in form
and color. _Zenopsis nebulosa_ and _Zen itea_ also occur on the coasts
of Japan. The remaining _Zeidæ_ (_Cyttus_, _Zenopsis_, _Zenion_, etc.)
are all rare species occasionally dredged especially in the Australian
region. _Zeus priscus_ is recorded from the Tertiary, and _Cyttoides
glaronensis_ from the upper Eocene of Glavus.

=Grammicolepidæ.=—The _Grammicolepidæ_, represented by a single species,
_Grammicolepis brachiusculus_, rarely taken off the coast of Cuba, is
related to the _Zeidæ_. It has rough, ridged, parchment-like scales
deeper than long. The ventrals are thoracic, with the rays in increased
number, as in _Zeus_ and _Beryx_, with each of which it suggests
affinity.



                               CHAPTER XV
                               BERYCOIDEI


=THE Berycoid Fishes.=—We may place in a separate order a group of
fishes, mostly spiny-rayed, which appeared earlier in geological time
than any other of the spinous forms, and which in several ways represent
the transition from the isospondylous fishes to those of the type of the
mackerel and perch. In the berycoid fishes the ventral fins are always
thoracic, the number of rays almost always greater than I, 5, and in all
cases an orbitosphenoid bone is developed in connection with the septum
between the orbits above. This bone is found in the _Isospondyli_ and
other primitive fishes, but according to the investigations of Mr. E. C.
Starks it is wanting in all percoid and scombroid forms, as well as in
the _Haplomi_ and in all the higher fishes. This trait may therefore,
among thoracic fishes, be held to define the section or suborder of
_Berycoidei_.

[Illustration:

  FIG. 198.—Skull of a Berycoid fish, _Beryx splendens_ Cuv. & Val.,
    showing the orbitosphenoid (OS), characteristic of all Berycoid
    fishes.
]

These fishes, most primitive of the thoracic types, were more abundant
in Cretaceous and Eocene times than now. The possession of an increased
number of soft rays in the ventral fins is archaic, although in one
family, the _Monocentridæ_, the number is reduced to three. Most of the
living _Berycoidei_ retain through life the archaic duct to the
air-bladder characteristic of most abdominal or soft-rayed fishes. In
some however, the duct is lost. For the first time in the fish series
the number of twenty-four vertebræ appears. In most spiny-rayed fishes
of the tropics, of whatever family, this number is retained.

In every case spines are present in the dorsal fin, and in certain cases
the development of the spinous dorsal surpasses that of the most extreme
perch-like forms. In geological times the Berycoids preceded all other
perch-like fishes. They are probably ancestral to all the latter. All
the recent species, in spite of high specialization, retain some archaic
characters.

=The Alfonsinos: Berycidæ.=—The typical family, _Berycidæ_, is composed
of fishes of rather deep water, bright scarlet or black in color, with
the body short and compressed, the scales varying in the different
genera. The single dorsal fin has a few spines in front, and there are
no barbels. The suborbitals are not greatly developed.

[Illustration:

  FIG. 199.—_Beryx splendens_ Lowe. Gulf Stream.
]

The species of _Beryx_, called in Spanish _Alfonsino_, _Beryx elegans_
and _Beryx decadactylus_, are widely distributed at moderate depths, the
same species being recorded from Portugal, Madeira, Cuba, the Gulf
Stream, and Japan. The colors are very handsome, being scarlet with
streaks of white or golden. These fishes reach the length of a foot or
more and are valued as food where sufficiently common.

Numerous species of _Beryx_ and closely allied genera are found in all
rocks since Cretaceous times; _Beryx dalmaticus_, from the Cretaceous of
Dalmatia, is perhaps the earliest. _Beryx insculptus_ is found in New
Jersey, but no other Berycoids are yet known as fossils from North
America. _Sphenocephalus_, with four anal spines, is found in the chalk,
as are also species of _Acrogaster_ and _Pycnosterinx_, these being the
earliest of fishes with distinctly spiny fins.

[Illustration:

  FIG. 200.—_Hoplopteryx lewesiensis_ (Mantell), restored. English
    Cretaceous Family _Berycidæ_. (After Woodward.)
]

The _Trachichthyidæ_ are deep-sea fishes with short bodies, cavernous
skulls, and rough scales. The dorsal is short, with a few spines in
front. The suborbitals are very broad, often covering the cheeks, and
the anal fin is shorter than the dorsal, a character which separates
these fishes from the _Berycidæ_, in which group the anal fin is very
long. The belly has often a serrated edge, and the coloration is red or
black, the black species being softer in body and living in deeper
water. Species of _Hoplostethus_, notably _Hoplostethus mediterraneus_,
are found in most seas at a considerable depth. _Trachichthys_, a genus
scarcely distinguishable from _Hoplostethus_, is found in various seas.
The genus _Paratrachichthys_ is remarkable for the anterior position of
the vent, much as in _Aphredoderus_. Species occur in Japan and
Australia. _Gephyroberyx_, with the dorsal fin notched, is known from
Japan (_G. japonicus_) and Madeira (_G. darwini_).

We may also refer to the _Trachichthyidæ_ certain species of still
deeper waters, black in color and still softer in texture, with smaller
scales which are often peculiar in form. These constitute the genera
_Caulolepis_, _Anoplogaster_, _Melamphaës_, and _Plectromus_. In
_Caulolepis_ the jaws are armed with very strong canines.

Allied to the _Trachichthyidæ_ are also the fossil genera _Hoplopteryx_
and _Homonotus_. _Hoplopteryx lewesiensis_, from the English chalk, is
one of the earliest of the spiny-rayed fishes.

[Illustration:

  FIG. 201.—_Paratrachichthys prosthemius_ Jordan & Fowler, Misaki,
    Japan. Family _Trachichthyidæ_.
]

=The Soldier-fishes: Holocentridæ.=—The soldier-fishes (_Holocentridæ_),
also known as squirrel-fishes, Welshmen, soldados, matajuelos, malau,
alehi, etc., are shore fishes very characteristic of rocky banks in the
tropical seas. In this family the flesh is firm and the large scales
very hard and with very rough edges. There are eleven spines in the
dorsal and four in the anal, the third being usually very long. The
ventral fins have one spine and seven soft rays. The whole head and body
are rough with prickles. The coloration is always brilliant, the ground
hue being scarlet or crimson, often with lines or stripes of white,
black, or golden. The fishes are valued as food, and they furnish a
large part of the beauty of coloration so characteristic of the fishes
of the coral reefs. The species are active, pugnacious, carnivorous, but
not especially voracious, the mouth being usually small.

[Illustration:

  FIG. 202.—Soldier-fish, _Holocentrus ascenscionis_ (Osbeck).
]

[Illustration:

  FIG. 203.—Soldier-fish, _Holocentrus ittodai_ Jordan & Fowler. Riu Kiu
    Islands, Japan.
]

The genus _Holocentrus_ is characterized by the presence of a large
spine on the angle of the preopercle. Its species are especially
numerous, _Holocentrus ascenscionis_, abundant in Cuba, ranges northward
in the Gulf Stream. _Holocentrus suborbitalis_, the mojarra cardenal, is
a small, relatively dull species swarming about the rocks of western
Mexico. _Holocentrus spinosissimus_ is a characteristic fish of Japan.
Many other species abound throughout Polynesia and the East Indies, as
well as in tropical America. _Holocentrus ruber_ and _Holocentrus
diadema_ are common species of Polynesia and the East Indies. Other
abundant species are _H. spinifer_, _H. microstomus_, and _H.
violascens_.

_Holocentrus marianus_ is the marian of the French West Indies.
_Holocentrus sammara_, and related large-mouthed species occur in
Polynesia.

[Illustration:

  FIG. 204.—_Ostichthys japonicus_ (Cuv. & Val.). Giran, Formosa.
]

In _Myripristis_ the preopercular spine is wanting and the air-bladder
is divided into two parts, the anterior extending to the ear.
_Myripristis jacobus_ is the brilliantly colored candil, or "Frère
Jacques," of the West Indies. Species of _Myripristis_ are known in
Hawaii as _u-u_. A curious method of catching _Myripristis murdjan_ is
pursued on the Island of Hawaii. A living fish is suspended by a cord in
front of a reef inhabited by this species. It remains with scarlet fins
spread and glistening red scales. Its presence is a challenge to other
individuals, who rush out to attack it. These are then drawn out by a
concealed scoop-net, and a fresh specimen is taken as a decoy.
_Myripristis pralinius_, _M. multiradiatus_, and other species occur in
Polynesia. _Ostichthys_ is allied to _Myripristis_ but with very large
rough scales. _Ostichthys japonicus_ is a large and showy fish of the
waters of Japan. _Ostichthys pillwaxi_ occurs at Honolulu. _Holotrachys
lima_ is a small, brick-red fish with small very rough scales found
throughout Polynesia.

Fossil species of _Holocentrus_, _Myripristis_, and related extinct
genera occur in the Eocene and Miocene. _Holocentrus macrocephalus_,
from Monte Bolca Eocene, is one of the best known. _Myricanthus
leptacanthus_ from the same region, has very slender spines in the fins.

[Illustration:

  FIG. 205.—Pine-cone Fish, _Monocentris japonicus_ (Houttuyn). Waka,
    Japan.
]

=The Polymixiidæ.=—The family of _Polymixiidæ_, or barbudos, is one of
the most interesting in Ichthyology from its bewildering combination of
characters belonging to different groups. With the general aspect of a
Berycoid, the ventral rays I, 7, and the single dorsal fin with a few
spines, _Polymixia_ has the scales rather smooth and at the chin are two
long barbels which look remarkably like those of the family of _Mullidæ_
or _Surmullets_. As in the _Mullidæ_, there are but four
branchiostegals. In other regards the two groups seem to have little in
common. According to Starks, the specialized feelers at the chin are
different in structure and must have been independently developed in the
two groups. In _Polymixia_, each barbel is suspended from the hypohyal;
three rudimentary branchiostegals forming its thickened base. In
_Mullus_, each barbel is suspended from the trip of a slender projection
of the ceratohyal, having no connection with the branchiostegals.
_Polymixia_ possesses the orbitosphenoid bone and is a true berycoid,
while the _Mullidæ_ are genuine percoid fishes.

Four species of _Polymixia_ are recorded from rather deep water:
_Polymixia nobilis_ from Madeira, _Polymixia lowei_ from the West
Indies, _Polymixia berndti_ from Hawaii, and _Polymixia japonica_ from
Japan. All are plainly colored, without red.

=The Pine-cone Fishes: Monocentridæ.=—Among the most extraordinary of
all fishes is the little family of _Monocentridæ_, or pine-cone fishes.
_Monocentris japonicus_, the best-known species, is common on the coasts
of Japan. It reaches the length of five inches. The body is covered with
a coat of mail, made of rough plates which look as though carelessly put
together. The dorsal spines are very strong, and each ventral fin is
replaced by a very strong rough spine. The animal fully justifies the
remark of its discoverer, Houttuyn (1782), that it is "the most
remarkable fish which exists." It is dull golden brown in color, and in
movement as sluggish as a trunkfish. A similar species, called
knightfish, _Monocentris gloriæ-maris_, is found in Australia. No
fossils allied to _Monocentris_ are known.



                              CHAPTER XVI
                              PERCOMORPHI


=SUBORDER Percomorphi, the Mackerels and Perches.=—We may place in a
single suborder the various groups of fishes which cluster about the
perches, and the mackerels. The group is not easily definable and may
contain heterogeneous elements. We may, however, arrange in it, for our
present purposes, those spiny-rayed fishes having the ventral fins
thoracic, of one spine and five rays (the ventral fin occasionally
wanting or defective, having a reduced number of rays), the lower
pharyngeal bones separate, the suborbital chain without backward
extension or bony stay, the post-temporal normally developed and
separate from the cranium, the premaxillary and maxillary distinct, the
cranium itself without orbitosphenoid bone, having a structure not
greatly unlike that of perch or mackerel, and the back-bone primitively
of twenty-four vertebræ, the number increased in arctic, pelagic, or
fresh-water offshoots.

The species, comprising the great body of the spiny-rayed forms, group
themselves chiefly about two central families, the _Scombridæ_, or
mackerels, and the _Serranidæ_, the sea-bass, with their fresh-water
allies, the _Percidæ_, or perch.

=The Mackerel Tribe: Scombroidea.=—The two groups of _Percomorphi_, the
mackerel-like and the perch-like, admit of no exact definition, as the
one fully grades into the other. The mackerel-like forms, or
_Scombroidea_, as a whole are defined by their adaptation for swift
movement. The profile is sharp anteriorly, the tail slender, with widely
forked caudal; the scales are usually small, thin, and smooth, of such a
character as not to produce friction in the water.

In general the external surface is smooth, the skeleton light and
strong, the muscles firm, and the species are carnivorous and
predaceous. But among the multitude of forms are many variations, and
some of these will seem to be exceptions to any definition of
mackerel-like fishes which could possibly be framed.

The mackerels, or _Scombroidea_, have usually the tail very slender,
composed of very strong bones, with widely forked fin. In the perch and
bass the tail is stout, composed largely of flesh, the supporting
vertebræ relatively small and spread out fan-fashion behind. Neither
mackerels nor perch nor any of their near allies ever have more than
five soft rays in the ventral fins, and the persistence of this number
throughout the _Percomorphi_, _Squamipinnes_, _Pharyngognathi_, and
spiny fishes generally must be attributed to inheritance from the
primitive perch-like or mackerel-like forms. In almost all the groups to
be considered in this work, after the _Berycoidea_ the ventral rays are
I, 5, or else fewer through degeneration, never more. In the central or
primitive members of most of these groups there are twenty-four
vertebræ, the number increased in certain forms, probably through
repetitive degeneration.

=The True Mackerels: Scombridæ.=—We may first consider the great central
family of _Scombridæ_, or true mackerels, distinguished among related
families by their swift forms, smooth scales, metallic coloration, and
technically by the presence of a number of detached finlets behind the
dorsal and anal fins. The cut of the mouth is peculiar, the spines in
the fins are feeble, the muscular system is extremely strong, the flesh
oily, and the air-bladder reduced in size or altogether wanting. As in
most swift-swimming fishes and fishes of pelagic habit, the vertebræ are
numerous and relatively small, an arrangement which promotes flexibility
of body. It is not likely that this group is the most primitive of the
scombroid fishes. In some respects the _Stromateidæ_ stand nearer the
primitive stock. The true mackerels, however, furnish the most
convenient point of departure in reviewing the great group.

In the genus of true mackerels, _Scomber_, the dorsal fins are well
separated, the first being rather short, and the scales of the shoulders
are not modified to form a corselet. There are numerous species, two of
them of general interest. The common mackerel, _Scomber scombrus_, is
one of the best known of food-fishes. It is probably confined to the
Atlantic, where on both shores it runs in vast schools, the movements
varying greatly from season to season, the preference being for cool
waters. The female mackerel produces about 500,000 eggs each year,
according to Professor Goode. These are very minute and each is provided
with an oil-globule, which causes it to float on the surface. About
400,000 barrels of mackerel are salted yearly by the mackerel fleet of
Massachusetts. Single schools of mackerel, estimated to contain a
million barrels, have been recorded. Captain Harding describes such a
school as "a windrow of fish half a mile wide and twenty miles long."

[Illustration:

  FIG. 206.—Mackerel, _Scomber scombrus_ L. New York.
]

Professor Goode writes:

"Upon the abundance of mackerel depends the welfare of many thousands of
the citizens of Massachusetts and Maine. The success of the
mackerel-fishery is much more uncertain than that of the cod-fishery,
for instance, for the supply of cod is quite uniform from year to year.
The prospects of each season are eagerly discussed from week to week in
thousands of little circles along the coast, and are chronicled by the
local press. The story of each successful trip is passed from mouth to
mouth, and is a matter of general congratulation in each fishing
community. A review of the results of the American mackerel-fishery, and
of the movements of the fish in each part of the season, would be an
important contribution to the literature of the American fisheries.

"The mackerel-fishery is peculiarly American, and its history is full of
romance. There are no finer vessels afloat than the American
mackerel-schooners—yachts of great speed and unsurpassed for
seaworthiness. The modern instruments of capture are marvels of
inventive skill, and require the highest degree of energy and
intelligence on the part of the fishermen. The crews of the
mackerel-schooners are still for the most part Americans of the old
colonial stock, although the cod and halibut fisheries are to a great
extent given up to foreigners.

"When the mackerel is caught, trout, bass, and sheepshead cannot
vanquish him in a gastronomic tournament. In Holland, to be sure, the
mackerel is not prized, and is accused of tasting like rancid fish-oil,
and in England, even, they are usually lean and dry, like the wretched
skeletons which are brought to market in April and May by the southern
fleet, which goes forth in the early spring from Massachusetts to
intercept the schools as they approach the coasts of Carolina and
Virginia. They are not worthy of the name of mackerel. _Scomber
Scombrus_ is not properly in season until the spawning time is over,
when the schools begin to feed at the surface in the Gulf of Maine and
the 'North Bay.'

"Just from the water, fat enough to broil in its own drippings, or
slightly corned in strong brine, caught at night and eaten in the
morning, a mackerel or a bluefish is unsurpassable. A well-cured autumn
mackerel is perhaps the finest of all salted fish, but in these days of
wholesale capture by the purse-seine, hasty dressing and careless
handling, it is very difficult to obtain a sweet and sound salt
mackerel. Salt mackerel may be boiled as well as broiled, and a fresh
mackerel may be cooked in the same manner. Americans will usually prefer
to do without the sauce of fennel and gooseberry which transatlantic
cooks recommend. Fresh and salt, fat and lean, new or stale, mackerel
are consumed by Americans in immense quantities, as the statistics show,
and whatever their state, always find ready sale."

Smaller, less important, less useful, but far more widely distributed is
the chub-mackerel, or thimble-eyed mackerel, _Scomber japonicus_
(Houttuyn, 1782), usually known by the later name of _Scomber colias_
(Gmelin, 1788). In this species the air-bladder (absent in the common
mackerel) is moderately developed. It very much resembles the true
mackerel, but is of smaller size, less excellence as a food-fish, and
keeps nearer to the shore. It may be usually distinguished by the
presence of vague, dull-gray spots on the sides, where the true mackerel
is lustrous silvery.

This fish is common in the Mediterranean, along our Atlantic coast, on
the coast of California, and everywhere in Japan.

_Scomber antarcticus_ is the familiar mackerel of Australia. _Scomber
loo_, silvery, with round black spots, is the common mackerel of the
South Seas, locally known as _Ga_.

_Scomber priscus_ is a fossil mackerel from the Eocene.

_Auxis thazard_, the frigate mackerel, has the scales of the shoulders
enlarged and somewhat coalescent, forming what is called a corselet. The
species ranges widely through the seas of the world in great numbers,
but very erratic, sometimes myriads reaching our Eastern coast, then
none seen for years. It is more constant in its visits to Japan and
Hawaii. Fossil species of _Auxis_ are found in the Miocene.

The genus _Gymnosarda_ has the corselet as in _Auxis_, but the first
dorsal fin is long, extending backward to the base of the second. Its
two species, _Gymnosarda pelamis_, the Oceanic bonito, and _Gymnosarda
alleterata_, the little tunny, are found in all warm seas, being
especially abundant in the Mediterranean, about Hawaii and Japan. These
are plump fish of moderate size, with very red and very oily flesh.

Closely related to these is the great tunny, or Tuna (_Thunnus thynnus_)
found in all warm seas and reaching at times a weight of 1500 pounds.
These enormous fishes are much valued by anglers, a popular "Tuna Club"
devoted to the sport of catching them with a hook having its
headquarters at Avalon, on Santa Catalina Island, in California. They
are good food, although the flesh of the large ones is very oily. The
name horse-mackerel is often given to these monsters on the New England
coast. In California, the Spanish name of tuna has become current among
fisherman.

Very similar to the tuna, but much smaller, is the Albacore (_Germo
alalonga_). This reaches a weight of fifteen to thirty pounds, and is
known by its very long, almost ribbon-like pectoral fins. This species
is common in the Mediterranean, and about the Santa Barbara Islands,
where it runs in great schools in March. The flesh of the albacore is of
little value, unless, as in Japan, it is eaten raw. The Japanese shibi
(_Germo germo_) is another large albacore, having the finlets bright
yellow. It is found also at Hawaii.

The bonito (_Sarda sarda_) wanders far throughout the Atlantic,
abounding on our Atlantic coast as in the Mediterranean, coming inshore
in summer to spawn or feed. Its flesh is red and not very delicate,
though it may be reckoned as a fair food-fish. It is often served under
the name of "Spanish mackerel" to the injury of the reputation of the
better fish.

[Illustration:

  FIG. 207.—The Long-fin Albacore, _Germo alalunga_ (Gmelin). Gulf
    Stream.
]

Professor Goode writes:

"One of these fishes is a marvel of beauty and strength. Every line in
its contour is suggestive of swift motion. The head is shaped like a
minie bullet, the jaws fit together so tightly that a knife-edge could
scarcely pass between, the eyes are hard, smooth, their surfaces on a
perfect level with the adjoining surfaces. The shoulders are heavy and
strong, the contours of the powerful masses of muscle gently and evenly
merging into the straighter lines in which the contour of the body
slopes back to the tail. The dorsal fin is placed in a groove into which
it is received, like the blade of a clasp-knife in its handle. The
pectoral and ventral fins also fit into depressions in the sides of the
fish. Above and below, on the posterior third of the body, are placed
the little finlets, each a little rudder with independent motions of its
own, by which the course of the fish may be readily steered. The tail
itself is a crescent-shaped oar, without flesh, almost without scales,
composed of bundles of rays flexible, yet almost as hard as ivory. A
single sweep of this powerful oar doubtless suffices to propel the
bonito a hundred yards, for the polished surfaces of its body can offer
little resistance to the water. I have seen a common dolphin swimming
round and round a steamship, advancing at the rate of twelve knots an
hour, the effort being hardly perceptible. The wild duck is said to fly
seventy miles in an hour. Who can calculate the speed of the bonito? It
might be done by the aid of the electrical contrivances by which is
calculated the initial velocity of a projectile. The bonitoes in our
sounds to-day may have been passing Cape Colony or the Land of Fire day
before yesterday."

Another bonito, _Sarda chilensis_, is common in California; in Chile,
and in Japan. This species has fewer dorsal spines than the bonito of
the Atlantic, but the same size, coloration, and flesh. Both are blue,
with undulating black stripes along the side of the back.

The genus _Scomberomorus_ includes mackerels slenderer in form, with
larger teeth, no corselet, and the flesh comparatively pale and free
from oil.

[Illustration:

  FIG. 208.—The Spanish Mackerel, _Scomberomorus maculatus_ (Mitchill).
    New York.
]

_Scomberomorus maculatus_, the Spanish mackerel of the West Indies, is
one of the noblest of food-fishes. Its biography was written by Mitchill
almost a century ago in these words:

"A fine and beautiful fish; comes in July."

Goode thus writes of it:

"The Spanish mackerel is surely one of the most graceful of fishes. It
appeals as scarcely any other can to our love of beauty, when we look
upon it, as shown in Kilbourn's well-known painting, darting like an
arrow just shot from the bow, its burnished sides, silver flecked with
gold, thrown into bold relief by the cool green background of the
rippled sea; the transparent grays, opalescent whites, and glossy blacks
of its trembling fins enhance the metallic splendor of its body, until
it seems to rival the most brilliant of tropical birds. Kilbourn made
copies of his large painting on the pearly linings of seashells and
produced some wonderful effects by allowing the natural luster of the
mother-of-pearl to show through his transparent pigments and simulate
the brilliancy of the life-inspired hues of the quivering, darting
sea-sprite, whose charms even his potent brush could not properly
depict.

"It is a lover of the sun, a fish of tropical nature, which comes to us
only in midsummer, and which disappears with the approach of cold, to
some region not yet explored by ichthyologists. It is doubtless very
familiar in winter to the inhabitants of some region adjacent to the
waters of the Caribbean or the tropical Atlantic, but until this place
shall have been discovered it is more satisfactory to suppose that with
the bluefish and the mackerel it inhabits that hypothetical winter
resort to which we send the migratory fishes whose habits we do not
understand—the middle strata of the ocean, the floating beds of
Sargassum, which drift hither and thither under the alternate promptings
of the Gulf-stream currents and the winter winds."

The Spanish mackerel swims at the surface in moderate schools and is
caught in abundance from Cape May southward. Its white flesh is most
delicious, when properly grilled, and Spanish mackerel, like pampano,
should be cooked in no other way.

A very similar species, _Scomberomorus sierra_, occurs on the west coast
of Mexico. For some reason it is little valued as food by the Mexicans.
In California, the Monterey Spanish mackerel (_Scomberomorus concolor_)
is equally excellent as a food-fish. This fish lacks the spots
characteristic of most of its relatives. It was first found in the Bay
of Monterey, especially at Santa Cruz and Soquel, in abundance in the
autumn of 1879 and 1880. It has not, so far as is known, been seen
since, nor is the species recorded from any other coast.

The true Spanish mackerel has round, bronze-black spots upon its sides.
Almost exactly like it in appearance is the pintado, or sierra
(_Scomberomorus regalis_), but in this species the spots are oblong in
form. The pintado abounds in the West Indies. Its flesh is less delicate
than that of the more true Spanish mackerel. The name _sierra_, saw,
commonly applied to these fishes by Spanish-speaking people, has been
corrupted into _cero_ in some books on angling.

Still other Spanish mackerel of several species occur on the coasts of
India, Chile, and Japan.

The great kingfish, or cavalla (_Scomberomorus cavalla_), is a huge
Spanish mackerel of Cuba and the West Indies, reaching a weight of 100
pounds. It is dark iron-gray in color, one of the best of food-fishes,
and is unspotted, and its firm, rich flesh resembles that of the
barracuda.

Still larger is the great guahu, or peto, an immense sharp-nosed,
swift-swimming mackerel found in the East and West Indies, as well as in
Polynesia, reaching a length of six feet and a weight of more than a
hundred pounds. Its large knife-like teeth are serrated on the edge and
the color is almost black. _Acanthocybium solandri_ is the species found
in Hawaii and Japan. The American _Acanthocybium petus_, occasionally
also taken in the Mediterranean, may be the same species.

Fossil Spanish mackerels, tunnies, and albacores, as well as
representatives of related genera now extinct, abound in the Eocene and
Miocene, especially in northern Italy. Among them are _Scomber antiquus_
from the Miocene, _Scombrinus macropomus_ from the Eocene London clays,
much like _Scomber_, but with stronger teeth, _Sphyrænodus priscus_ from
the same deposits, the teeth still larger, _Scombramphodon crossidens_,
from the same deposits, also with strong teeth, like those of
_Scomberomorus_. _Scomberomorus_ is the best represented of all the
genera as fossil, _Scomberomorus speciosus_ and numerous other species
occurring in the Eocene. A fossil species of _Germo_, _G. lanceolatus_,
occurs at Monte Bolca in Eocene rocks. Another tunny, with very small
teeth is _Eothynnus salmonens_, from the lower Eocene near London.
Several other tunny-like fishes occur in the lower Tertiary.

=The Escolars: Gempylidæ.=—More predaceous than the mackerels and
tunnies are the pelagic mackerels, _Gempylidæ_, known as _escolars_
("scholars"), with the body almost band-shaped and the teeth very large
and sharp. Some of these, from the ocean depths, are violet-black in
color, those near the surface being silvery. _Escolar violaceus_ lives
in the abysses of the Gulf Stream. _Ruvettus pretiosus_, the black
escolar, lives in more moderate depths and is often taken in Cuba,
Madeira, Hawaii, and Japan. It is a very large fish, black, with very
rough scales. The flesh is white, soft, and full of oil; sometimes rated
very high, and at other times too rank to be edible. The name _escolar_
means _scholar_ in Spanish, but its root meaning, as applied to this
fish, comes from a word meaning _to scour_, in allusion to the very
rough scales.

_Promethichthys prometheus_, the rabbit-fish, or conejo, so-called from
its wariness, is caught in the same regions, being especially common
about Madeira and Hawaii. _Gempylus serpens_, the snake-mackerel, is a
still slenderer and more voracious fish of the open seas. _Thyrsites
atun_ is the Australian "barracuda," a valued food-fish, voracious and
predaceous.

=Scabbard-and Cutlass-fishes: Lepidopidæ and Trichiuridæ.=—The family of
_Lepidopidæ_, or scabbard-fishes, includes degenerate mackerels,
band-shaped, with continuous dorsal fin, and the long jaws armed with
very small teeth. These are found in the open sea, _Lepidopus candatus_
being the most common. This species reaches a length of five or six feet
and comes to different coasts occasionally to deposit its spawn. It
lives in warm water and is at once chilled by the least cold; hence the
name of frostfish occasionally applied to it. Several species of
_Lepidopus_ are fossil in the later Tertiary. _Lepidopus glarisianus_
occurs in the Swiss Oligocene, and with it _Thyrsitocephalus alpinus_,
which approaches more nearly to the _Gempylidæ_.

Still more degenerate are the _Trichiuridæ_, or cutlass-fishes, in which
the caudal fin is wanting, the tail ending in a hair-like filament. The
species are bright silvery in color, very slender, and very voracious,
reaching a length of three to five feet. _Trichiurus lepturus_ is rather
common on our Atlantic coast. The names hairfish and silver-eel, among
others, are often given to it. _Trichiurus japonicas_, a very similar
species, is common in Japan, and other species inhabit the tropical
seas. _Trichiurichthys_, a fossil genus with well-developed scales,
precedes _Trichiurus_ in the Miocene.

[Illustration:

  FIG. 209.—Cutlass-fish, _Trichiurus lepturus_ Linnæus. St. Augustine,
    Fla.
]

=The Palæorhynchidæ.=—The extinct family of _Palæorhynchidæ_ is found
from the Eocene to the Oligocene. It contains very long and slender
fishes, with long jaws and small teeth, the dorsal fin long and
continuous. The species resembles the _Escolar_ on the one hand and the
sailfishes on the other, and they may prove to be ancestral to the
_Istiophoridæ_. _Hemirhynchus deshayesi_ with the upper jaw twice as
long as the lower, sword-like, occurs in the Eocene at Paris;
_Palæorhynchum glarisianum_, with the jaws both elongate, the lower
longest, is in the Oligocene of Glarus. Several other species of both
genera are recorded.

[Illustration:

  FIG. 210.—_Palæorhynchus glarisianus_ Blainville. Oligocene. (After
    Woodward.)
]

=The Sailfishes: Istiophoridæ.=—Remotely allied to the cutlass-fishes
and still nearer to the _Palæorhynchidæ_ is the family of sailfishes,
_Istiophoridæ_, having the upper jaw prolonged into a sword made of
consolidated bones. The teeth are very feeble and the ventral fins
reduced to two or three rays. The species are few in number, of large
size, and very brilliant metallic coloration, inhabiting the warm seas,
moving northward in summer. They are excellent as food, similar to the
swordfish in this as in many other respects. The species are not well
known, being too large for museum purposes, and no one having critically
studied them in the field. _Istiophorus_ has the dorsal fin very high,
like a great sail, and undivided; _Istiophorus nigricans_ is rather
common about the Florida Keys, where it reaches a length of six feet.
Its great sail, blue with black spots, is a very striking object.
Closely related to this is _Istiophorus orientalis_ of Japan and other
less known species of the East Indies.

_Tetrapturus_, the spearfish, has the dorsal fin low and divided into
two parts. Its species are taken in most warm seas, _Tetrapturus
imperator_ throughout the Atlantic, _Tetrapturus amplus_ in Cuba,
_Tetrapturus mitsukurii_ and _Tetrapturus mazara_ in Japan. These much
resemble swordfish in form and habits, and they have been known to
strike boats in the same way.

Fossil _Istiophoridæ_ are known only from fragments of the snout, in
Europe and America, referred provisionally to _Istiophorus_. The genus
_Xiphiorhynchus_, fossil swordfishes from the Eocene, known from the
skull only, may be referred to this family, as minute teeth are present
in the jaws. _Xiphiorhynchus priscus_ is found in the London Eocene.

=The Swordfishes: Xiphiidæ.=—The family of swordfishes, _Xiphiidæ_,
consists of a single species, _Xiphias gladius_, of worldwide
distribution in the warm seas. The snout in the swordfish is still
longer, more perfectly consolidated, and a still more effective weapon
of attack. The teeth are wholly wanting, and there are no ventral fins,
while the second of the two fins on the back is reduced to a slight
finlet.

[Illustration:

  FIG. 211.—Young Swordfish, _Xiphias gladius_ (Linnæus). (After
    Lütken.)
]

The swordfish follows the schools of mackerel to the New England coasts.
"Where you see swordfish, you may know that mackerel are about," Goode
quotes from an old fisherman. The swordfish swims near the surface,
allowing its dorsal fin to appear, as also the upper lobe of the caudal.
It often leaps out of the water, and none of all the fishes of the sea
can swim more swiftly.

[Illustration:

  FIG. 212.—Swordfish, _Xiphias gladius_ (Linnæus). (After Day.)
]

"The pointed head," says Goode, "the fins of the back and abdomen snugly
fitting into grooves, the absence of ventrals, the long, lithe, muscular
body, sloping slowly to the tail, fit it for the most rapid and forcible
movement through the water. Prof. Richard Owen, testifying in an England
court in regard to its power, said:

"'It strikes with the accumulated force of fifteen double-handed
hammers. Its velocity is equal to that of a swivel-shot, and is as
dangerous in its effects as a heavy artillery projectile.'

"Many very curious instances are on record of the encounters of this
fish with other fishes, or of their attacks upon ships. What can be the
inducement for it to attack objects so much larger than itself it is
hard to surmise.

"It surely seems as if a temporary insanity sometimes takes possession
of the fish. It is not strange that, when harpooned, it should retaliate
by attacking its assailant. An old swordfish fisherman told Mr.
Blackford that his vessel had been struck twenty times. There are,
however, many instances of entirely unprovoked assault on vessels at
sea. Many of these are recounted in a later portion of this memoir.
Their movements when feeding are discussed below, as well as their
alleged peculiarities of movement during the breeding season.

"It is the universal testimony of our fishermen that two are never seen
swimming close together. Capt. Ashby says that they are always distant
from each other at least thirty or forty feet.

"The pugnacity of the swordfish has become a byword. Without any special
effort on my part numerous instances of their attacks upon vessels have
in the last ten years found their way into the pigeon-hole labeled
'Swordfish.'"

Swordfishes are common on both shores of the Atlantic wherever mackerel
run. They do not breed on our shores, but probably do so in the
Mediterranean and other warm seas. They are rare off the California
coast, but five records existing (Anacapa, Santa Barbara, Santa
Catalina, San Diego, off Cerros Island). The writer has seen two large
individuals in the market of Yokohama, but it is scarcely known in
Japan. As a food-fish, the swordfish is one of the best, its
dark-colored oily flesh, though a little coarse, making most excellent
steaks. Its average weight on our coast is about 300 pounds, the maximum
625.

The swordfish undergoes great change in the process of development, the
very young having the head armed with rough spines and in nowise
resembling the adult.

Fossil swordfishes are unknown, or perhaps cannot be distinguished from
remains of _Istiophoridæ_.



                              CHAPTER XVII
                         CAVALLAS AND PAMPANOS


=THE Pampanos: Carangidæ.=—We next take up the great family of Pampanos,
_Carangidæ_, distinguished from the _Scombridæ_ as a whole by the
shorter, deeper body, the fewer and larger vertebræ, and by the loss of
the provision for swift movement in the open sea characteristic of the
mackerels and their immediate allies. A simple mark of the _Carangidæ_
is the presence of two separate spines in front of the anal fin. These
spines are joined to the fin in the young. All of the species undergo
considerable changes with age, and almost all are silvery in color with
metallic blue on the back.

Most like the true mackerel are the "leather-jackets," or "runners,"
forming the genera _Scomberoides_ and _Oligoplites_. _Scomberoides_ of
the Old World has the body scaly, long, slender, and fitted for swift
motion; _Scomberoides sancti-petri_ is a widely diffused species, and
others are found in Polynesia. In the New World genus _Oligoplites_ the
scales are reduced to linear ridges imbedded in the skin at different
angles. _Oligoplites saurus_ is a common dry and bony fish abounding in
the West Indies and ranging north in summer to Cape Cod.

_Naucrates ductor_, the pilot-fish, or romero, inhabits the open sea,
being taken—everywhere rarely—in Europe, the West Indies, Hawaii, and
Japan. It is marked by six black cross-bands. Its tail has a keel, and
it reaches a length of about two feet. In its development it undergoes
considerable change, its first dorsal fin being finally reduced to
disconnected spines.

The amber-fishes, forming the genus _Seriola_, are rather robust fishes,
with the anal fin much shorter than the soft dorsal. The sides of the
tail have a low, smooth keel. From a yellow streak obliquely across the
head in some species they receive their Spanish name of coronado. The
species are numerous, found in all warm seas, of fair quality as food,
and range in length from two to six feet.

[Illustration:

  FIG. 213.—Pilot-fish, _Naucrates ductor_ (Linnæus). New Bedford, Mass.
]

[Illustration:

  FIG. 214.—Amber-fish, _Seriola lalandi_ (Cuv. & Val.). Family
    _Carangidæ_. Wood's Hole.
]

_Seriola dorsalis_ is the noted yellow-tail of California, valued by
anglers for its game qualities. It comes to the Santa Barbara Islands in
early summer. _Seriola zonata_ is the rudder-fish, or shark's pilot,
common on our New England coast. The banded young, abundant off Cape
Cod, lose their marks with age. _Seriola hippos_ is the "samson-fish" of
Australia. _Seriola lalandi_ is the great amber-fish of the West Indies,
occasionally venturing farther northward, and _Seriola dumerili_ the
amber-jack, or coronado, of the Mediterranean. The deep-bodied medregal
(_Seriola fasciata_) is also taken in the West Indies, as is also the
high-finned _Seriola rivoliana_. Species very similar to these occur in
Hawaii and Japan, where they are known as _Ao_, or bluefishes. _Seriola
lata_ is fossil in the mountains of Tuscany.

The runner, _Elegatis bipinnulatus_, differs from _Seriola_ in having a
finlet behind dorsal and anal. It is found in almost all warm seas,
ranging north once in a while to Long Island.

The mackerel scads (_Decapterus_) have also a finlet, and on the
posterior part of the body the lateral line is shielded with bony
plates. In size and form these little fishes much resemble small
mackerel, and they are much valued as food wherever abundant.
_Decapterus punclatus_, known also as cigar-fish and round-robin,
frequently visits our Atlantic coasts from the West Indies, where it is
abundant. _Decapterus russelli_ is the _Maruaji_, highly valued in Japan
for its abundance, while _Decapterus muroadsi_ is the Japanese muroaji.

[Illustration:

  FIG. 215.—The Saurel, _Trachurus trachurus_ (Linnæus). Newport, R. I.
]

_Megalaspis cordyla_ abounds in the East Indies and Polynesia. It has
many finlets, and the bony plates on the lateral line are developed to
an extraordinary degree.

In _Trachurus_ the finlets are lost and the bony plates extend the whole
length of the lateral line. The species known as saurel and wrongly
called horse-mackerel are closely related and some of them very widely
distributed.

_Trachurus trachurus_ common in Europe, extends to Japan where it is the
abundant maaji. _Trachurus mediterraneus_ is common in southern Europe
and _Trachurus symmetricus_ in California. _Trachurus picturatus_ of
Madeira is much the same as the last named, and there is much question
as to the right names and proper limits of all these species.

In _Trachurops_ the bony plates are lacking on the anterior half of the
body, and there is a peculiar nick and projection on the lower part of
the anterior edge of the shoulder-girdle. _Trachurops crumenophthalma_,
the goggler, or big-eyed scad, ranges widely in the open sea and at
Hawaii, as the _Akule_, is the most highly valued because most abundant
of the migratory fishes. At Samoa it is equally abundant, the name being
here _Atule_. _Trachurops torva_ is the meaji, or big-eyed scad, of the
Japanese, always abundant.

[Illustration:

  FIG. 216.—Yellow Mackerel, _Carangus chrysos_ (Mitchill). Wood's Hole.
]

To _Caranx_, _Carangus_, and a number of related genera, characterized
by the bony armature on the narrow caudal peduncle, a host of species
may be referred. These fishes, known as cavallas, hard-tails, jacks,
etc., are broad-bodied, silvery or metallic black in color, and are
found in all warm seas. They usually move from the tropics northward in
the fall in search of food and are especially abundant on our Atlantic
coast, in Polynesia, and in Japan. About the Oceanic Islands they are
resident, these being their chosen spawning-grounds. In Hawaii and Samoa
they form a large part of the food-supply, the ulua (_Carangus
forsteri_) and the malauli (_Carangus melampygus_) being among the most
valuable food-fishes, large in size and excellent in flesh, unsurpassed
in fish chowders. Of the American species _Carangus chrysos_, called
yellow mackerel, is the most abundant, ranging from Cape Cod southward.
This is an elongate species of moderate size. The cavalla, or jiguagua,
_Carangus hippos_, known by the black spot on the opercle, with another
on the pectoral fin, is a widely distributed species and one of the
largest of the tribe. Another important food-fish is the horse-eye-jack,
or jurel, _Carangus latus_, which is very similar to the species called
ulua in the Pacific. The black jack, or tiñosa, of Cuba, _Carangus
funebris_, is said to be often poisonous. This is a very large species,
black in color, the sale of which has been long forbidden in the markets
of Havana. The young of different species of _Carangus_ are often found
taking refuge under the disk of jelly-fishes protected by the stinging
feelers. The species of the genus _Carangus_ have well-developed teeth.
In the restricted genus of _Caranx_ proper, the jaws are toothless.
_Caranx speciosus_, golden with dark cross-bands, is a large food-fish
of the Pacific. _Citula armata_ is another widely distributed species,
with some of the dorsal rays produced in long filaments.

In _Alectis ciliaris_, the cobbler-fish, or threadfish, the armature of
the tail is very slight and each fin has some of its rays drawn out into
long threads. In the young these are very much longer than the body, but
with age they wear off and grow shorter, while the body becomes more
elongate. In _Vomer_, _Selene_, and _Chloroscombrus_ the bony armature
of the tail, feeble in _Alectis_, by degrees entirely disappears.

_Vomer setipinnis_, the so-called moonfish, or jorobado, has the body
greatly elevated, compressed, and distorted, while the fins, growing
shorter with age, become finally very low. _Selene vomer_, the
horse-head-fish, or look-down (see Fig. 113, Vol. I), is similarly but
even more distorted. The fins, filamentous in the young, grow shorter
with age, as in _Vomer_ and _Alectis_. The skeleton in these fishes is
essentially like that of _Carangus_, the only difference lying in the
compression and distortion of the bones. _Chloroscombrus_ contains the
casabes, or bumpers, thin, dry, compressed fish, of little value as
food, the bony armature of the tail being wholly lost.

To the genus _Trachinotus_ belong the pampanos, broad-bodied, silvery
fishes, toothless when adult, the bodies covered with small scales and
with no bony plates.

The true pampano, _Trachinotus carolinus_, is one of the finest of all
food-fishes, ranking with the Spanish mackerel and to be cooked in the
same way, only by broiling. The flesh is white, firm, and flaky, with a
moderate amount of delicate oil. It has no especial interest to the
angler and it is not abundant enough to be of great commercial
importance, yet few fish bring or deserve to bring higher prices in the
markets of the epicures. The species is most common along our Gulf
coast, ranging northward along the Carolinas as far as Cape Cod.

[Illustration:

  FIG. 217.—The Pampano, _Trachinotus carolinus_ (Linnæus). Wood's Hole.
]

Pampano in Spanish means the leaf of the grape, from the broad body of
the fish. The spelling "pompano" should therefore be discouraged.

The other pampanos, of which there are several in tropical America and
Asia, are little esteemed, the flesh being dry and relatively
flavorless. _Trachinotus palometa_, the gaff-topsail pampano, has very
high fins and its sides have four black bands like the marks of a grill.
The round pampano, _Trachinotus falcatus_, is common southward, as is
also the great pampano, _Trachinotus goodei_, which reaches a length of
three feet. _Trachinotus ovatus_, a large deep-bodied pampano, is common
in Polynesia and the East Indies. No pampanos are found in Europe, but a
related genus, _Lichia_, contains species which much resemble them, but
in which the body is more elongate and the mouth larger.

Numerous fossils are referred to the _Carangidæ_ with more or less
certainty. _Aipichthys pretiosus_ and other species occur in the
Cretaceous. These are deep-bodied fishes resembling _Seriola_, having
the falcate dorsal twice as long as the anal and the ventral ridge with
thickened scales. _Vomeropsis_ (_longispina elongata_, etc.), also from
the Eocene, with rounded caudal, the anterior dorsal rays greatly
elongate, and the supraoccipital crest highly developed, probably
constitutes with it a distinct family, _Vomeropsidæ_. Several species
referable to _Carangus_ are found in the Miocene. _Archæus glarisianus_,
resembling _Carangus_, but without scales so far as known, is found in
the Oligocene of Glarus; _Seriola prisca_ and other species of _Seriola_
occur in the Eocene; _Carangopsis brevis_, etc., allied to _Caranx_, but
with the lateral line unarmed, is recorded from the Eocene of France and
Italy.

_Ductor leptosomus_ from the Eocene of Monte Bolca resembles
_Naucrates_; _Trachinotus tenuiceps_ is recorded from Monte Bolca, and a
species of uncertain relationship, called _Pseudovomer minutus_, with
sixteen caudal vertebræ is taken from the Miocene of Licata.

=The Papagallos: Nematistiidæ.=—Very close to the _Carangidæ_, and
especially to the genus _Seriola_, is the small family of
_Nematistiidæ_, containing the papagallo, _Nematistius pectoralis_ of
the west coast of Mexico. This large and beautiful fish has the general
appearance of an amber-fish, but the dorsal spines are produced in long
filaments. The chief character of the family is found in the excessive
division of the rays of the pectoral fins.

=The Bluefishes: Cheilodipteridæ.=—Allied to the _Carangidæ_ is the
family of bluefishes (_Cheilodipteridæ_, or _Pomatomidæ_). The single
species _Cheilodipterus saltatrix_, or _Pomatomus saltatrix_, known as
the bluefish, is a large, swift, extremely voracious fish, common
throughout most of the warmer parts of the Atlantic, but very
irregularly distributed on the various coasts. Its distribution is
doubtless related to its food. It is more abundant on our Eastern coast
than anywhere else, and its chief food here is the menhaden. The
bluefish differs from the _Carangidæ_ mainly in its larger scales, and
in a slight serration of the bones of the head. Its flesh is tender and
easily torn. As a food-fish, rich, juicy, and delicate, it has few
superiors. Its maximum weight is from twelve to twenty pounds, but most
of those taken are much smaller. It is one of the most voracious of all
fish. Concerning this, Professor Baird observes:

[Illustration:

  FIG. 218.—Bluefish, _Cheilodipterus saltatrix_ (L.). New York.
]

"There is no parallel in point of destructiveness to the bluefish among
the marine species on our coast, whatever may be the case among some of
the carnivorous fish of the South American waters. The bluefish has been
well likened to an animated chopping-machine the business of which is to
cut to pieces and otherwise destroy as many fish as possible in a given
space of time. All writers are unanimous in regard to the
destructiveness of the bluefish. Going in large schools in pursuit of
fish not much inferior to themselves in size, they move along like a
pack of hungry wolves, destroying everything before them. Their trail is
marked by fragments of fish and by the stain of blood in the sea, as,
where the fish is too large to be swallowed entire, the hinder portion
will be bitten off and the anterior part allowed to float away or sink.
It is even maintained with great earnestness that such is the gluttony
of the fish, that when the stomach becomes full the contents are
disgorged and then again filled. It is certain that it kills many more
fish than it requires for its own support.

"The youngest fish, equally with the older, perform this function of
destruction, and although they occasionally devour crabs, worms, etc.,
the bulk of their sustenance throughout the greater part of the year is
derived from other fish. Nothing is more common than to find a small
bluefish of six or eight inches in length under a school of minnows
making continual dashes and captures among them. The stomachs of the
bluefish of all sizes, with rare exceptions, are found loaded with the
other fish, sometimes to the number of thirty or forty, either entire or
in fragments.

"As already referred to, it must also be borne in mind that it is not
merely the small fry that are thus devoured, and which it is expected
will fall a prey to other animals, but that the food of the bluefish
consists very largely of individuals which have already passed a large
percentage of the chances against their reaching maturity, many of them,
indeed, having arrived at the period of spawning. To make the case more
clear, let us realize for a moment the number of bluefish that exist on
our coast in the summer season. As far as I can ascertain by the
statistics obtained at the fishing-stations on the New England coast, as
also from the records of the New York markets, kindly furnished by
Middleton & Carman, of the Fulton Market, the capture of bluefish from
New Jersey to Monomoy during the season amounts to no less than one
million individuals, averaging five or six pounds each. Those, however,
who have seen the bluefish in his native waters and realized the immense
numbers there existing will be quite willing to admit that probably not
one fish in a thousand is ever taken by man. If, therefore, we have an
actual capture of one million, we may allow one thousand millions as
occurring in the extent of our coasts referred to, even neglecting the
smaller ones, which, perhaps, should also be taken into account.

"An allowance of ten fish per day to each bluefish is not excessive,
according to the testimony elicited from the fishermen and substantiated
by the stomachs of those examined; this gives ten thousand millions of
fish destroyed per day. And as the period of the stay of the bluefish on
the New England coast is at least one hundred and twenty days, we have
in round numbers twelve hundred million millions of fish devoured in the
course of a season. Again, if each bluefish, averaging five pounds,
devours or destroys even half its own weight of other fish per day (and
I am not sure that the estimate of some witnesses of twice this weight
is not more nearly correct), we will have, during the same period, a
daily loss of twenty-five hundred million pounds, equal to three hundred
thousand millions for the season.

"This estimate applies to three or four year old fish of at least three
to five pounds in weight. We must, however, allow for those of smaller
size, and a hundred-fold or more in number, all engaged simultaneously
in the butchery referred to.

"We can scarcely conceive of a number so vast; and however much we may
diminish, within reason, the estimate of the number of bluefish and the
average of their capture, there still remains an appalling aggregate of
destruction. While the smallest bluefish feed upon the diminutive fry,
those of which we have taken account capture fish of large size, many of
them, if not capable of reproduction, being within at least one or two
years of that period.

"It is estimated by very good authority that of the spawn deposited by
any fish at a given time not more than 30 per cent. are hatched, and
that less than 10 per cent. attain an age when they are able to take
care of themselves. As their age increases the chances of reaching
maturity become greater and greater. It is among the small residuum of
this class that the agency of the bluefish is exercised and whatever
reasonable reduction may be made in our estimate, we cannot doubt that
they exert a material influence.

"The rate of growth of the bluefish is also an evidence of the immense
amount of food they must consume. The young fish which first appear
along the shores of Vineyard Sound, about the middle of August, are
about five inches in length. By the beginning of September, however,
they have reached six or seven inches, and on their reappearance in the
second year they measure about twelve or fifteen inches. After this they
increase in a still more rapid ratio. A fish which passes eastward from
Vineyard Sound in the spring weighing five pounds is represented,
according to the general impression, by the ten to fifteen-pound fish of
the autumn. If this be the fact, the fish of three or four pounds which
pass along the coast of North Carolina in March return to it in October
weighing ten to fifteen pounds.

"As already explained, the relationship of these fish to the other
inhabitants of the sea is that of an unmitigated butcher; and it is able
to contend successfully with any other species not superior to itself in
size. It is not known whether an entire school ever unite in an attack
upon a particular object of prey, as is said to be the case with the
ferocious fishes of the South American rivers; should they do so, no
animal, however large, could withstand their onslaught.

"They appear to eat anything that swims of suitable size—fish of all
kinds, but perhaps more especially the menhaden, which they seem to
follow along the coast, and which they attack with such ferocity as to
drive them on the shore, where they are sometimes piled up in windrows
to the depth of a foot or more."

=The Sergeant-fishes: Rachycentridæ.=—The _Rachycentridæ_, or
sergeant-fishes, are large, strong, swift, voracious shore fishes, with
large mouths and small teeth, ranging northward from the warm seas. The
dorsal spines are short and stout, separate from the fin, and the body
is almost cylindrical, somewhat like that of the pike.

[Illustration:

  FIG. 219.—Sergeant-fish, _Rachycentron canadum_ (Linnæus). Virginia.
]

_Rachycentron canadum_, called cobia, crab-eater, snooks, or
sergeant-fish, reaches a length of about five feet. The last name is
supposed to allude to the black stripe along its side, like the stripe
on a sergeant's trousers. It is rather common in summer along our
Atlantic coast as far as Cape Cod, especially in Chesapeake Bay.
_Rachycentron pondicerrianum_, equally voracious, extends its summer
depredations as far as Japan. The more familiar name for these fishes,
_Elacate_, is of later date than _Rachycentron_.

Mr. Prime thus speaks of the crab-eater as a game-fish:

"In shape he may be roughly likened to the great northern pike, with a
similar head, flattened on the forehead. He is dark green on the back,
growing lighter on the sides, but the distinguishing characteristic is a
broad, dark collar over the neck, from which two black stripes or
straps, parting on the shoulders, extend, one on each side, to the tail.
He looks as if harnessed with a pair of traces, and his behavior on a
fly-rod is that of a wild horse. The first one that I struck, in the
brackish water of Hillsborough River at Tampa, gave me a hitherto
unknown sensation. The tremendous rush was not unfamiliar, but when the
fierce fellow took the top of the water and went along lashing it with
his tail, swift as a bullet, then descended, and with a short, sharp,
electric shock left the line to come home free, I was for an instant
confounded. It was all over in ten seconds. Nearly every fish that I
struck after this behaved in the same way, and after I had got 'the hang
of them' I took a great many."

=The Butter-fishes: Stromateidæ.=—The butter-fishes (_Stromateidæ_) form
a large group of small fishes with short, compressed bodies, smooth
scales, feeble spines, the vertebræ in increased number and especially
characterized by the presence of a series of tooth-like processes in the
œsophagus behind the pharyngeals. The ventral fins present in the young
are often lost in the process of development.

According to Mr. Regan, the pelvic bones are very loosely attached to
the shoulder-girdle as in the extinct genera _Platycormus_ and
_Homosoma_. This is perhaps a primitive feature, indicating the line of
descent of these fishes from berycoid forms.

We unite with the _Stromateidæ_ the groups or families of
_Centrolophidæ_ and _Nomeidæ_, knowing no characters by which to
separate them.

_Stromateus fiatola_, the fiatola of the Italian fishermen, is an
excellent food-fish of the Mediterranean. _Poronotus triacanthus_, the
harvest-fish, or dollar-fish, of our Atlantic coast, is a common little
silvery fish six to ten inches, as bright and almost as round as a
dollar. Its tender oily flesh has an excellent flavor. Very similar to
it is the poppy-fish (_Palometa simillima_) of the sandy shores of
California, miscalled the "California pampano," valued by the San
Francisco epicure, who pays large prices for it supposing it to be
pampano, although admitting that the pampano in New Orleans has firmer
flesh and better flavor. The harvest-fish, _Peprilus paru_, frequently
taken on our Atlantic coast, is known by its very high fins.
_Stromateoides argenteus_, a much larger fish than any of these, is a
very important species on the coasts of China.

[Illustration:

  FIG. 220.—Harvest-fish, _Peprilus paru_ (Linnæus). Virginia.
]

_Psenopsis anomala_ takes the place of our butter-fishes in Japan, and
much resembles them in appearance as in flavor.

To the _Stromateidæ_ we also refer the black ruff of Europe,
_Centrolophus niger_, an interesting deep-sea fish rarely straying to
our coast. Allied to it is the black rudder-fish, _Palinurichthys
perciformis_, common on the Massachusetts coast, where it is of some
value as a food-fish. A specimen in a live-box once drifted to the coast
of Cornwall, where it was taken uninjured, though doubtless hungry.
Other species of ruff-and rudder-fish are recorded from various coasts.

Allied to the _Stromateidæ_ are numerous fossil forms. _Omosoma
sachelalmæ_ and other species occur in the Cretaceous at Mount Lebanon.
_Platycormus germanus_, with ctenoid scales resembling a berycoid, but
with the ventral rays I, 5, occurs in the Upper Cretaceous. Closely
related to this is _Berycopsis elegans_, with smoother scales, from the
English Chalk.

[Illustration:

  FIG. 221.—Portuguese Man-of-war Fish, _Gobiomorus gronovii_. Family
    _Stromateidæ_.
]

_Gobiomorus gronovii_ (usually called _Nomeus gronovii_), the Portuguese
man-of-war-fish, is a neat little fish about three inches long, common
in the Gulf of Mexico and the Gulf Stream, where it hides from its
enemies among the poisoned tentacles of the Portuguese man-of-war. Under
the Portuguese man-of-war and also in or under large jelly-fishes
several other species are found, notably _Carangus medusicola_ and
_Peprilus paru_. Many small species of _Psenes_, a related genus, also
abound in the warm currents from tropical seas.

=The Rag-fishes: Icosteidæ.=—Allied to the butter-fishes are the
deep-water _Icosteidæ_, fishes of soft, limp bodies as unresistant as a
wet rag, _Icosteus ænigmaticus_ of the California coast being known as
ragfish. _Schedophilus medusophagus_ feeds on medusæ and salpa, living
on the surface in the deep seas. Mr. Ogilby thus speaks of a specimen
taken in Ireland:

"It was the most delicate adult fish I ever handled; within twenty-four
hours after its capture the skin of the belly and the intestines fell
off when it was lifted, and it felt in the hand quite soft and
boneless." A related species (_S. heathi_) has been lately taken by Dr.
Charles H. Gilbert at Monterey in California.

The family of _Acrotidæ_ contains a single species of large size.
_Acrotus willoughbyi_, allied to _Icosteus_, but without ventral fins
and with the vertebræ very numerous. The type, five and one-quarter feet
long, was thrown by a storm on the coast of Washington, near the
Quinnault agency.

The family of _Zaproridæ_ contains also a single large species, _Zaprora
silenus_, without ventrals, but scaly and firm in substance. One
specimen 2½ feet long was taken at Nanaimo on Vancouver Island and a
smaller one at Victoria.

=The Pomfrets: Bramidæ.=—The _Bramidæ_ are broad-bodied fishes of the
open seas, covered with firm adherent scales. The flesh is firm and the
skeleton heavy, the hypercoracoid especially much dilated. Of the
various species the pomfret, or black bream (_Brama raii_), is the best
known and most widely diffused. It reaches a length of two to four feet
and is sooty black in color. It is not rare in Europe and has been
occasionally taken at Grand Bank off Newfoundland, at the Bermudas, off
the coast of Washington, on Santa Catalina Island, and in Japan. It is
an excellent food-fish, but is seldom seen unless driven ashore by
storms.

_Steinegeria rubescens_ of the Gulf of Mexico is a little-known deep-sea
fish allied to _Brama_, but placed by Jordan and Evermann in a distinct
family, _Steinegeriidæ_.

Closely related to the _Bramidæ_ is the small family of _Pteraclidæ_,
silvery fishes with large firm scales, living near the surface in the
ocean currents. In these fishes the ventral fins are placed well
forward, fairly to be called jugular, and the rays of the dorsal and
anal, all inarticulate or spine-like, are excessively prolonged. The
species, none of them well known, are referred to four genera—
_Pteraclis_, _Bentenia_, _Centropholis_, and _Velifer_. They are
occasionally taken in ocean currents, chiefly about Japan and Madeira.

Fossil forms more or less remotely allied to the _Bramidæ_ are recorded
from the Eocene and Miocene. Among these are _Acanthonemus_, and perhaps
_Pseudovomer_.

=The Dolphins: Coryphænidæ.=—The dolphins, or dorados (_Coryphænidæ_),
are large, swift sea-fishes, with elongate, compressed bodies, elevated
heads, sharp like the cut-water of a boat, and with the caudal fin very
strong. The long dorsal fin, elevated like a crest on the head, is
without spines. The high forehead characteristic of the dolphin is
developed only in the adult male. The flesh of the dolphin is valued as
food. Its colors, golden-blue with deep-blue spots, fade rapidly at
death, though the extent of this change has been much exaggerated.
Similar changes of color occur at death in most bright-colored fishes,
especially in those with thin scales. The common dolphin, or dorado
(_Coryphæna hippurus_), is found in all warm seas swimming near the
surface, as usual in predatory fishes, and reaches a length of about six
feet. The small dolphin, _Coryphæna equisetis_, rarely exceeds 2½ feet,
and is much more rare than the preceding, from which the smaller number
of dorsal rays (53 instead of 60) best distinguishes it. Young dolphins
of both species are elongate in form, the crest of the head not
elevated, the physiognomy thus appearing very different from that of the
adult. _Goniognathus coryphænoides_ is an extinct dolphin of the Eocene.

[Illustration:

  FIG. 222.—Dolphin or Dorado, _Coryphæna hippurus_ Linnæus. New York.
]

The name dolphin, belonging properly to a group of small whales or
porpoises, the genus _Delphinus_, has been unfortunately used in
connection with this very different animal, which bears no resemblance
to the mammal of the same name.

Other mackerel-like families not closely related to these occur in the
warm seas. The _Leiognathidæ_ are small, silvery fishes of the East
Indies. _Leiognathus argentatus_ (_Equula_) is very common in the bays
of Japan, a small silvery fish of moderate value as food. _Gazza
minuta_, similar, with strong teeth, abounds farther south. _Leiognathus
fasciatum_ is common in Polynesia. A fossil species called _Parequula
albyi_ occurs in the Miocene of Licata.

The _Kurtidæ_ are small, short-bodied fishes of the Indian seas, with
some of the ribs immovably fixed between rings formed by the ossified
cover of the air-bladder and with the hypocoracoid obsolete. _Kurtus
indicus_ is the principal species.

=The Menidæ.=—Near the _Kurtidæ_ we may perhaps place the family of
_Menidæ_, of one species, _Mene maculata_, the moonfish of the open seas
of the East Indies and Japan. This is a small fish, about a foot long,
with the body very closely compressed, the fins low and the belly,
through the extension of the pelvic bone, a good deal more prominent
than the back. The ventral fins have the usual number of one spine and
five soft rays, a character which separates _Mene_ widely from
_Lampris_, which in some ways seems allied to it.

[Illustration:

  FIG. 223.—_Mene maculata_ (Bloch & Schneider). Family Menidæ. Japan.
]

Another species of _Menidæ_ is the extinct _Gasteronemus rhombeus_ of
the Eocene of Monte Bolca. It has much the same form, with long pubic
bones. The very long ventral fins are, however, made of one spine and
one or two rays. A second species, _Gasteronemus oblongus_, is recorded
from the same rocks.

=The Pempheridæ.=—The _Pempheridæ_, "deep-water catalufas," or "magifi,"
are rather small deep-bodied fishes, reddish in color, with very short
dorsal, containing a few graduated spines, and with a very long anal
fin. These inhabit tropical seas at moderate depths. _Pempheris_ bears a
superficial resemblance to _Beryx_, but, according to Starks, this
resemblance is not borne out by the anatomy. _Pempheris mulleri_ and _P.
poeyi_ are found in the West Indies. _Pempheris otaitensis_ and _P.
mangula_ range through Polynesia.

[Illustration:

  FIG. 224.—_Gasteronemus rhombeus_ Agassiz. (After Woodward.) Menidæ.
]

[Illustration:

  FIG. 225.—Catalufa de lo Alto, _Pempheris mulleri_ Poey. Havana.
]

[Illustration:

  FIG. 226.—_Pempheris nyctereutes_ Jordan & Evermann. Giran, Formosa.
]

[Illustration:

  FIG. 227.—The Louvar, _Luvarus imperialis_ Rafinesque. Family
    Luvaridæ. (After Day.)
]

Very close to the _Pempheridæ_ is the small family of _Bathyclupeidæ_.
These are herring-like fishes, much compressed and with a duct to the
air-bladder. There are but one or two dorsal spines. The ventrals are of
one spine and five rays as in perch-like fishes, but placed behind the
pectoral fins. This feature, due to the shortening of the belly, is
regarded by Alcock, the discoverer, as a result of degeneration, and the
family was placed by him among the herrings. The persistent air-duct
excludes it from the _Percesoces_, the normally formed ventrals from the
_Berycoidei_. If we trust the indications of the skeleton, we must place
the family with _Pempheris_, near the scombroid fishes.

=Luvaridæ.=—Another singular family is the group of _Louvars_,
_Luvaridæ_. _Luvaris imperialis._ The single known species is a large,
plump, voracious fish, with the dorsal and anal rays all unbranched, and
the scales scurf-life over the smooth skin. It is frequently taken in
the Mediterranean, and was found on the island of Santa Catalina,
California, by Mr. C. F. Holden.

=The Square-tails: Tetragonuridæ.=—The _Tetragonuridæ_ are long-bodied
fishes of a plump or almost squarish form, covered with hard, firm, very
adherent scales. _Tetragonurus cuvieri_, the single species, called
square-tail, or escolar de natura, is a curious fish, looking as if
whittled out of wood, covered with a compact armor of bony scales, and
swimming very slowly in deep water. It is known from the open Atlantic
and Mediterranean and has been once taken at Wood's Hole in
Massachusetts. According to Mr. C. T. Regan the relations of this
eccentric fish are with the _Stromateidæ_ and _Bramidæ_, the skeleton
being essentially that of _Stromateus_, and Boulenger places both
_Tetragonurus_ and _Stromateus_ among the _Percesoces_.

=The Crested Bandfishes: Lophotidæ.=—The family of _Lophotidæ_ consists
of a few species of deep-sea fishes, band-shaped, naked, with the dorsal
of flexible spines beginning as a high crest on the elevated occiput.
The first spine is very strong. The ventrals are thoracic with the
normal number, I, 5, of fin-rays. _Lophotes cepedianus_, the crested
bandfish, is occasionally taken in the Mediterranean in rather deep
water. _Lophotes capellei_ is rarely taken in the deep waters of Japan.

It is thought that the _Lophotidæ_ may be related to the ribbon-fishes,
_Tæniosomi_, but on the whole they seem nearer to the highly modified
_Scombroidei_, the _Pteraclidæ_ for example.

In a natural arrangement, we should turn from the _Bramidæ_ to the
_Antigoniidæ_ and the _Ilarchidæ_, then passing over the series which
leads through _Chætodontidæ_ and _Teuthidæ_ to the _Plectognaths_. It
is, however, necessary to include here, alongside the mackerels, though
not closely related to them, the parallel series of perch-like fishes,
which at the end become also hopelessly entangled, through aberrant
forms, with other series of which the origin and relations are
imperfectly understood. As the relations of forms cannot be expressed in
a linear series, many pages must intervene before we can take up the
supposed line of development from the Scombroid fishes to those called
_Squamipinnes_.



                             CHAPTER XVIII
                    PERCOIDEA, OR PERCH-LIKE FISHES


=PERCOID Fishes.=—We may now take up the long series of the _Percoidea_,
the fishes built on the type of the perch or bass. This is a group of
fishes of diverse habits and forms, but on the whole representing better
than any other the typical _Acanthopterygian_ fish. The group is
incapable of concise definition, or, in general, of any definition at
all; still, most of its members are definitely related to each other and
bear in one way or another a resemblance to the typical form, the perch,
or more strictly to its marine relatives, the sea-bass, or _Serranidæ_.
The following analysis gives most of the common characters of the group:

Body usually oblong, covered with scales, which are typically ctenoid,
not smooth nor spinous, and of moderate size. Lateral line typically
present and concurrent with the back. Head usually compressed laterally
and with the cheeks and opercles scaly. Mouth various, usually terminal
and with lateral cleft; the teeth various, but typically pointed,
arranged in bands on the jaws, and in several families on the vomer and
palatine bones also, as well as on the pharyngeals; gill-rakers usually
sharp, stoutish, armed with teeth, but sometimes short or feeble; lower
pharyngeals almost always separate, usually armed with cardiform teeth;
third upper pharyngeal moderately enlarged, elongate, not articulated to
the cranium, the fourth typically present; gills four, a slit behind the
fourth; gill membranes free from the isthmus, and usually not connected
with each other; pseudobranchiæ typically well developed.
Branchiostegals few, usually six or seven. No bony stay connecting the
suborbital chain to the preopercle. Opercular bones all well developed,
normal in position; the preopercle typically serrate. No cranial spines.
Dorsal fin variously developed, but always with some spines in front,
these typically stiff and pungent; anal fin typically short, usually
with three spines, sometimes with a larger number, rarely with none;
caudal fin various, usually lunate; pectoral fins well developed,
inserted high; ventral fins always present, thoracic, separate, almost
always with one spine and five rays, the _Aphredoderidæ_ having more, a
few _Serranidæ_ having fewer. Air-bladder usually present, without
air-duct in adult; simple and generally adherent to the walls of the
abdomen. Stomach cæcal, with pyloric appendages, the intestines short in
most species, long in the herbivorous forms. Vertebral column well
developed, none of the vertebræ especially modified, the number 10 + 14
= 24, except in certain extratropical and fresh-water forms, which
retain primitive higher numbers. Shoulder-girdle normally developed, the
post-temporal bifurcate attached to the skull, but not coossified with
it; none of the epipleural bones attached to the center of the vertebræ;
coracoids normal, the hypercoracoid always with a median foramen, the
basal bones of the pectoral (actinosts or pterygials) normally
developed, three or four in number, hour-glass-shaped, longer than
broad; premaxillary forming the border of the mouth usually protractile;
bones of the mandible distinct. Orbitosphenoid wanting.

The most archaic of the perch-like types are apparently some of those of
the fresh waters. Among these the process of evolution has been less
rapid. In some groups, as the _Percidæ_, the great variability of
species is doubtless due to the recent origin, the characters not being
well fixed.

=The Pirate-perches: Aphredoderidæ.=—Among the most remarkable of the
living percoid fishes and probably the most primitive of all, showing
affinities with the _Salmopercæ_, is the pirate-perch, _Aphredoderus
sayanus_, a little fish of the lowland streams of the Mississippi
Valley. The family of _Aphredoderidæ_ agrees with the berycoid fishes in
scales and structure of the fins, and Boulenger places it with the
Berycidæ. Starks has shown, however, that it lacks the orbitosphenoid,
and the general osteology is that of the perch-like fishes. The dorsal
and anal have a few spines. The thoracic ventrals have one spine and
eight rays. There is no adipose fin and probably no duct to the
air-bladder. A singular trait is found in the position of the vent. In
the adult this is in front of the ventral fins, at the throat. In the
young it is behind the ventral fins as in ordinary fishes. With age it
moves forward by the prolongation of the horizontal part of the
intestine or rectum. The same peculiar position of the vent is found in
the berycoid genus _Paratrachichthys_.

[Illustration:

  FIG. 228.—Pirate Perch, _Aphredoderus sayanus_ (Gilliams). Illinois
    River.
]

[Illustration:

  FIG. 229.—Everglade Pigmy Perch, _Elassoma evergladei_ Jordan.
    Everglades of Florida.
]

In the family _Aphredoderidæ_ but one species is known, _Aphredoderus
sayanus_, the pirate-perch. It reaches a length of five inches and lives
in sluggish lowland streams with muddy bottom from New Jersey and
Minnesota to Louisiana. It is dull green in color and feeds on insects
and worms. It has no economic value, although extremely interesting in
its anatomy and relationship.

Whether the _Asineopidæ_, fresh-water fishes of the American Eocene, and
the _Erismatopteridæ_, of the same deposits (see page 235) are related
to _Aphredoderus_ or to _Percopsis_ is still uncertain.

[Illustration:

  FIG. 230.—Skull of the Rock Bass, _Ambloplites rupestris_.
]

=The Pigmy Sunfishes: Elassomidæ.=—One of the most primitive groups is
that of _Elassomidæ_, or pigmy sunfishes. These are very small fishes,
less than two inches long, living in the swamps of the South, resembling
the sunfishes, but with the number of dorsal spines reduced to from
three to five. _Elassoma zonatum_ occurs from southern Illinois to
Louisiana. _Elassoma evergladei_ abounds in the Everglades of Florida.
In both the body is oblong and compressed, the color is dull green
crossed by black bars or blotches.

=The Sunfishes: Centrarchidæ.=—The large family of _Centrarchidæ_, or
sunfishes, is especially characteristic of the rivers of the eastern
United States, where the various species are inordinately abundant. The
body is relatively short and deep, and the axis passes through the
middle so that the back has much the same outline as the belly. The
pseudobranchiæ are imperfect, as in many fresh-water fishes, and the
head is feebly armed, the bones being usually without spines or
serratures. The colors are often brilliant, the sexes alike, and all are
carnivorous, voracious, and gamy, being excellent as food. The origin of
the group is probably Asiatic, the fresh-water serranoid of Japan,
_Bryttosus_, resembling in many ways an American sunfish, and the genus
_Kuhlia_ of the Pacific showing many homologies with the black bass,
_Micropterus_.

[Illustration:

  FIG. 231.—Crappie, _Pomoxis annularis_ Rafinesque. Ohio River.
]

[Illustration:

  FIG. 232.—Crappie, _Pomoxis annularis_ (Raf.). (From life by Dr. R. W.
    Shufeldt.)
]

[Illustration:

  FIG. 233.—Rock Bass, _Ambloplites rupestris_ (Rafinesque.) Ecorse,
    Mich.
]

[Illustration:

  FIG. 234.—Banded Sunfish, _Mesogonistius chætodon_ (Baird). Delaware
    River.
]

=Crappies and Rock Bass.=—_Pomoxis annularis_, the crappie, and _Pomoxis
sparoides_, the calico-bass, are handsome fishes, valued by the angler.
These are perhaps the most primitive of the family, and in these species
the anal fin is larger than the dorsal. The flier, or round bass,
_Centrarchus macropterus_, with eight anal spines, is abundant in swamps
and lowland ponds of the Southern States. It is a pretty fish,
attractive in the aquarium. _Acantharchus pomotis_ is the mud-bass of
the Delaware, and _Archoplites interruptus_, the "perch" of the
Sacramento. The latter is a large and gamy fish, valued as food and
interesting as being the only fresh-water fish of the nature of perch or
bass native to the west of the Rocky Mountains. The numbers of this
species, according to Mr. Will S. Green of Colusa, California, have been
greatly reduced by the introduction of the catfish (_Ameiurus
nebulosus_) into the Sacramento. The perch eats the young catfish, and
its stomach is torn by their sharp pectoral spines. Another species of
this type is the warmouth (_Chænobryttus gulosus_) of the ponds of the
South, and still more familiar rock-bass or redeye (_Ambloplites
rupestris_) of the more northern lakes and rivers valued as a game-and
food-fish. A very pretty aquarium fish is the black-banded sunfish,
_Mesogonistius chætodon_, of the Delaware, as also the nine-spined
sunfish, _Enneacanthus gloriosus_, of the coast streams southward.
_Apomotis cyanellus_, the blue-green sunfish or little redeye, is very
widely distributed from Ohio westward, living in every brook. The
dissection of this species is given on page 26, Vol. I. To _Lepomis_
belong numerous species having the opercle prolonged in a long flap
which is always black in color, often with a border of scarlet or blue.
The yellowbelly of the South (_Lepomis auritus_), ear-like the showily
colored long-eared sunfish (_Lepomis megalotis_) of the southwest,
figured on page 2, Vol. I, the bluegill (_Lepomis pallidus_), abundant
everywhere south and west of New York, are members of this genus. The
genus _Eupomotis_ differs in its larger pharyngeals, which are armed
with blunt teeth. The common sunfish, or pumpkinseed, _Eupomotis
gibbosus_, is the most familiar representative of the family, abounding
everywhere from Minnesota to New England, then south to Carolina on the
east slope of the Alleghanies, breeding everywhere in ponds and in the
eddies of the clear brooks.

[Illustration:

  FIG. 235.—Blue-Gill, _Lepomis pallidus_ (Mitchill). Potomac River.
]

[Illustration:

  FIG. 236.—Long-eared Sunfish, _Lepomis megalotis_ (Rafinesque). From
    Clear Creek, Bloomington, Indiana. Family _Centrarchidæ_.
]

[Illustration:

  FIG. 237.—Common Sunfish, _Eupomotis gibbosus_ (Linnæus). Root River,
    Wis.
]

=The Black Bass.=—The black bass (_Micropterus_) belong to the same
family as the sunfish, differing in the larger size, more elongate form,
and more voracious habit. The two species are among the most important
of American game-fishes, abounding in all clear waters east of the
Alleghanies and resisting the evils of civilization far better than the
trout.

The small-mouthed black bass, _Micropterus dolomieu_, is the most
valuable of the species. Its mouth, although large, is relatively small,
the cleft not extending beyond the eye. The green coloration is broken
in the young by bronze cross-bands. The species frequents only running
streams, preferring clear and cold waters, and it extends its range from
Canada as far to the southward as such streams can be found. Dr. James
A. Henshall, an accomplished angler, author of the "Book of the Black
Bass," says: "The black bass is eminently an American fish; he has the
faculty of asserting himself and of making himself completely at home
wherever placed. He is plucky, game, brave, unyielding to the last when
hooked. He has the arrowy rush and vigor of a trout, the untiring
strength and bold leap of a salmon, while he has a system of fighting
tactics peculiarly his own. I consider him inch for inch and pound for
pound the gamest fish that swims."

In the same vein Charles Hallock writes: "No doubt the bass is the
appointed successor of the trout; not through heritage, nor selection,
nor by interloping, but by foreordination. Truly, it is sad to
contemplate, in the not distant future, the extinction of a beautiful
race of creatures, whose attributes have been sung by all the poets; but
we regard the inevitable with the same calm philosophy with which the
astronomer watches the burning out of a world, knowing that it will be
succeeded by a new creation. As we mark the soft varitinted flush of the
trout disappear in the eventide, behold the sparkle of the coming bass,
as he leaps in the morning of his glory! We hardly know which to admire
the most—the velvet livery and the charming graces of the departing
courtier, or the flash of the armor-plates of the advancing warrior. The
bass will unquestionably prove himself a worthy substitute for his
predecessor and a candidate for a full legacy of honors.

"No doubt, when every one of the older states shall become as densely
settled as Great Britain itself, and all the rural aspects of the
crowded domain resemble the suburban surroundings of our Boston; when
every feature of the pastoral landscape shall wear the finished
appearance of European lands, and every verdant field be closely cropped
by lawn-mowers and guarded by hedges, and every purling stream which
meanders through it has its water-bailiff, we shall still have speckled
trout from which the radiant spots have faded, and tasteless fish, to
catch at a dollar a pound (as we already have on Long Island), and all
the appurtenances and appointments of a genuine English trouting
privilege and a genuine English 'outing.'

[Illustration:

  FIG. 238.—Small Mouth Black Bass, _Micropterus dolomieu_ Lacépède.
]

"In those future days, not long hence to come, some venerable piscator,
in whose memory still lingers the joy of fishing, the brawling stream
which tumbled over the rocks in the tangled wildwood, and moistened the
arbutus and the bunchberries which garnished its banks, will totter
forth to the velvet edge of some peacefully flowing stream, and having
seated himself on a convenient point in a revolving easy-chair, placed
there by his careful attendant, cast right and left for the semblance of
sport long dead.

"Hosts of liver-fed fish rush to the signal for their early morning
meal, and from the center of the boil which follows the fall of the
handfuls thrown in my piscator of the ancient days will hook a two-pound
trout, and play him hither and yon, from surface to bottom, without
disturbing the pampered gourmands which are gorging themselves upon the
disgusting viands; and when he has leisurely brought him to land at
last, and the gillie has scooped him with his landing-net, he will feel
in his capacious pocket for his last trade dollar, and giving his friend
the tip, shuffle back to his house, and lay aside his rod forever."

The black bass is now introduced into the streams of Europe and
California. There is little danger that it will work injury to the
trout, for the black bass prefers limestone streams, and the trout
rarely does well in waters which do not flow over granite rock or else
glacial gravel.

The large-mouth black bass (_Micropterus salmoides_) is very much like
the other in appearance. The mouth is larger, in the adult cleft beyond
the eye; the scales are larger, and in the young there is always a broad
black stripe along the sides and no cross-bands. The two are found in
the same region, but almost never in the same waters, for the
large-mouth bass is a fish of the lakes, ponds, and bayous, always
avoiding the swift currents. The young like to hide among weeds or
beneath lily-pads. From its preference for sluggish waters, its range
extends farther to the southward, as far as the Mexican State of
Tamaulipas.

_Plioplarchus_ is a genus of fossil sunfishes from the Eocene of South
Dakota and Oregon. _Plioplarchus sexspinosus_, _septemspinosus_, and
_whitei_ are imperfectly known species.

=The Saleles: Kuhliidæ.=—Much like the sunfishes in anatomy, though more
like the white perch in appearance and habit, are the members of the
little family of _Kuhliidæ_. These are active silvery perches of the
tropical seas, ponds, and river-mouths, especially abundant in
Polynesia. _Kuhlia malo_ is the aholehole of the Hawaiians, a silvery
fish living in great numbers in brackish waters. _Kuhlia rupestris_, the
salele of the Samoan rivers, is a large swift fish of the rock pools, in
form, color, and habits remarkably like the black bass. It is silvery
bronze in hue, everywhere mottled with olive-green. The sesele, _Kuhlia
marginata_, lives with it in the rivers, but is less abundant. The
saboti, _Kuhlia tæniura_, a large silvery fish with cross-bands on the
caudal fin, lives about lava-rooks in Polynesia from the Galapagos to
Samoa and the East Indies, never entering rivers. Still other species
are found in the rock pools and streams of Japan and southward.

The skeleton in _Kuhlia_ is essentially like that of the black bass, and
Dr. Boulenger places the genus with the _Centrarchidæ_.

=The True Perches: Percidæ.=—The great family of _Percidæ_ includes
fresh-water fishes of the northern hemisphere, elongate in body, with
the vertebræ in increased number and with only two spines in the anal
fin. About ninety species are recorded, the vast majority being
American. The dwarf perches, called darters (_Etheostominæ_), are
especially characteristic of the clear streams to the eastward of the
plains of the Missouri. These constitute one of the greatest attractions
of our American river fauna. They differ from the perch and its European
allies in their small size, bright colors, and large fins, and more
technically in the rudimentary condition of the pseudobranchiæ and the
air-bladder, both of which organs are almost inappreciable. The
preopercle is unarmed, and the number of the branchiostegals is six. The
anal papilla is likewise developed, as in the _Gobiidæ_, to which group
the darters bear a considerable superficial resemblance, which, however,
indicates no real affinity.

[Illustration:

  FIG. 239.—Large-mouthed Black Bass, _Micropterus salmoides_ (Lac.).
    (From life by Dr. R. W. Shufeldt.)
]

=Relations of Darters to Perches.=—The colors of the _Etheostominæ_, or
darters, are usually very brilliant, species of _Etheostoma_ especially
being among the most brilliantly colored fishes known; the sexual
differences are often great, the females being, as a rule, dull in color
and more speckled or barred than the males. Most of them prefer clear
running water, where they lie on the bottom concealed under stones,
darting, when frightened or hungry, with great velocity for a short
distance, by a powerful movement of the fan-shaped pectorals, then
stopping as suddenly. They rarely use the caudal fin in swimming, and
they are seldom seen floating or moving freely in the water like most
fishes. When at rest they support themselves on their expanded ventrals
and anal fin. All of them can turn the head from side to side, and they
frequently lie with the head in a curved position or partly on one side
of the body. The species of _Ammocrypta_, and perhaps some of the
others, prefer a sandy bottom, where, by a sudden plunge, the fish
buries itself in the sand, and remains quiescent for hours at a time
with only its eyes and snout visible. The others lurk in stony places,
under rocks and weeds. Although more than usually tenacious of vitality,
the darters, from their bottom life, are the first to be disturbed by
impurities in the water. All the darters are carnivorous, feeding
chiefly on the larvæ of _Diptera_, and in their way voracious. All are
of small size; the largest (_Percina rex_) reaches a length of ten
inches, while the smallest (_Microperca punctulata_) is, one of the
smallest spiny-rayed fishes known, barely attaining the length of an
inch and a half. In Europe no _Etheostominæ_ are found, their place
being filled by the genera _Zingel_ and _Aspro_, which bear a strong
resemblance to the American forms, a resemblance which may be a clue to
the origin of the latter.

=The Perches.=—The European perch, _Perca fluviatilis_, is placed by
Cuvier at the head of the fish series, as representing in a high degree
the traits of a fish without sign of incomplete development on the one
hand or of degradation on the other. Doubtless the increased number of
the vertebræ is the chief character which would lead us to call in
question this time-honored arrangement. Because, however, the perch has
a relatively degenerate vertebral column, we have used an allied form,
the striped bass, as a fairer type of the perfected spiny-rayed fish.
Certainly the bass represents this type better than the perch.

But though we may regard the perch as nearest the typically perfect
fish, it is far from being one of the most highly specialized, for, as
we have seen in several cases, a high degree of specialization of a
particular structure is a first step toward its degradation.

The perch of Europe is a common game-fish of the rivers. The yellow
perch of America (_Perca flavescens_) is very much like it, a little
brighter in color, olive and golden with dusky cross-bands. It frequents
quiet streams and ponds from Minnesota eastward, then southward east of
the Alleghanies. "As a still-pond fish," says Dr. Charles Conrad Abbott,
"if there is a fair supply of spring-water, they thrive excellently; but
the largest specimens come either from the river or from the inflowing
creeks. Deep water of the temperature of ordinary spring-water, with
some current and the bed of the stream at least partly covered with
vegetation, best suits this fish." The perch is a food-fish of moderate
quality. In spite of its beauty and gaminess, it is little sought for by
our anglers, and is much less valued with us than is the European perch
in England. But Dr. Goode ventures to prophesy that "before many years
the perch will have as many followers as the black bass among those who
fish for pleasure" in the region it inhabits. "A fish for the people it
is, we will grant, and it is the anglers from among the people who have
neither time nor patience for long trips nor complicated tackle who will
prove its steadfast friends." The boy values it, according to Thoreau.
When he returns from the mill-pond, he numbers his perch as "real
fishes." "So many unquestionable fish he counts, and so many chubs,
which he counts, then throws away."

[Illustration:

  FIG. 240.—Yellow Perch, _Perca flavescens_ Mitchill. Potomac River.
]

In the perch, the oral valves, characteristic of all bony fishes, are
well developed. These structures recently investigated by Evelyn G.
Mitchill, form a fold of connective tissue just behind the premaxillary
and before the vomer. They are used in respiration, preventing the
forward flow of water as the mouth closes.

Several perch-like fishes are recorded as fossils from the Miocene.

Allied to the perch, but long, slender, big-mouthed, and voracious, is
the group of pike perches, found in eastern America and Europe. The
wall-eye, or glass-eye (_Stizostedion vitreum_), is the largest of this
tribe, reaching a weight of ten to twenty pounds. It is found throughout
the region east of the Missouri in the large streams and ponds, an
excellent food-fish, with white, flaky flesh and in the north a game
fish of high rank. The common names refer to the large glassy eye,
concerning which Dr. Goode quotes from some "ardent admirer" these
words: "Look at this beautiful fish, as symmetrical in form as the
salmon. Not a fault in his make-up, not a scale disturbed, every fin
perfect, tail clean-cut, and his great, big wall-eyes stand out with
that life-like glare so characteristic of the fish."

[Illustration:

  FIG. 241.—Sauger, _Stizostedion canadense_ (Smith). Ecorse, Mich.
]

Similar to the wall-eye, but much smaller and more translucent in color,
is the sauger, or sand-pike, of the Great Lakes and Northern rivers,
_Stizostedion canadense_. This fish rarely exceeds fifteen inches in
length, and as a food-fish it is of correspondingly less importance.

[Illustration:

  FIG. 242.—The Aspron, _Aspro asper_ (Linnæus). Rhone River. Family
    _Percidæ_. (After Seelye.)
]

The pike-perch, or zander, of central Europe, _Centropomus_ (or
_Sandrus_) _lucioperca_, is an excellent game-fish, similar to the
sauger, but larger, characterized technically by having the ventral fins
closer together. Another species, _Centropomus volgensis_, in Russia,
looks more like a perch than the other species do. _Sandroserrus_, a
fossil pike-perch, occurs in the Pliocene. Another European fish related
to the perch is the river ruff, or pope, _Acerina cernua_, which is a
small fish with the form of a perch and with conspicuous mucous cavities
in the skull. It is common throughout the north of Europe and especially
abundant at the confluence of rivers. _Gymnocephalus schrætzer_ of the
Danube has the head still more cavernous. _Percarina demidoffi_ of
southern Russia is another dainty little fish of the general type of the
perch. A fossil genus of this type called _Smerdis_ is numerously
represented in the Miocene and later rocks. The aspron, _Aspro asper_,
is a species like a darter found lying on the bottoms of swift rivers,
especially the Rhone. The body is elongate, with the paired fins highly
developed. _Zingel zingel_ is found in the Danube, as is also a third
species called _Aspro streber_. In form and coloration these species
greatly resemble the American darters, and the genus _Zingel_ is,
perhaps, the ancestor of the entire group. _Zingel_ differs from
_Percina_ mainly in having seven instead of six branchiostegals and the
pseudobranchiæ better developed. The differences in these and other
regards which distinguish the darters are features of degradation, and
they are also no doubt of relatively recent acquisition. To this fact we
may ascribe the difficulty in finding good generic characters within the
group. Sharply defined genera occur where the intervening types are
lost. The darter is one of the very latest products in the evolution of
fishes.

[Illustration:

  FIG. 243.—The Zingel, _Zingel zingel_ (Linnæus). Danube River. (After
    Seelye.)
]

=The Darters: Etheostominæ.=—Of the darters, or etheostomine perches,
over fifty species are known, all confined to the streams of the region
bounded by Quebec, Assiniboia, Colorado, and Nuevo Leon. All are small
fishes and some of them minute, and some are the most brilliantly
colored of all fresh-water fishes of any region, the most ornate
belonging to the large genus called _Etheostoma_. The largest species,
the most primitive because most like the perch, belong to the genus
_Percina_.

First among the darters because largest in size, most perch-like in
structure, and least degenerate, we place the king darter, _Percina rex_
of the Roanoke River in Virginia. This species reaches a length of six
inches, is handsomely colored, and looks like a young wall-eye.

[Illustration:

  FIG. 244.—Log-perch, _Percina caprodes_ (Rafinesque). Licking Co.,
    Ohio.
]

The log-perch, _Percina caprodes_, is near to this, but a little
smaller, with the body surrounded by black rings alternately large and
small. In this widely distributed species, large enough to take the
hook, the air-bladder is present although small. In the smaller species
it vanishes by degrees, and in proportion as in their habits they cling
to the bottom of the stream. The air-bladder is least developed in those
species which cling closest to the bottom of the stream.

[Illustration:

  FIG. 245.—Black-sided Darter, _Hadropterus aspro_ (Cope & Jordan).
    Chickamauga River.
]

The genus _Hadropterus_ includes many handsome species, most of them
with a black lateral band widened at intervals. The black-sided darter,
_Hadropterus aspro_, is the best-known species and one of the most
elegant of all fishes, abounding in the clear gravelly streams of the
Ohio basin and northwestward.

_Hadropterus evides_ of the Ohio region is still more brilliant, with
alternate bands of dark blue-green and orange-red, most exquisite in
their arrangement. In the South, _Hadropterus nigrofasciatus_, the
crawl-a-bottom of the Georgia rivers, is a heavily built darter, which
Vaillant has considered the ancestral species of the group. Still more
swift in movement and bright in color are the species of _Hypohomus_,
which flash their showy hues in the sparkling brooks of the Ozark and
the Great Smoky Mountains. _Hypohomus aurantiacus_ is the best-known
species.

[Illustration:

  FIG. 246.—Green-sided Darter, _Diplesion blennioides_ Rafinesque.
    Clinch River. Family _Percidæ_.
]

_Diplesion blennioides_, the green-sided darter, is the type of numerous
species with short heads, large fins, and coloration of speckled green
and golden. It abounds in the streams of the Ohio Valley.

[Illustration:

  FIG. 247.—Tessellated Darter, _Boleosoma olmstedi_ (Storer). Potomac
    River.
]

The tessellated darters, _Boleosoma_, are the most plainly colored of
the group and among the smallest; yet in the delicacy, wariness, and
quaintness of motion they are among the most interesting, especially in
the aquarium. _Boleosoma_ _nigrum_, the Johnny darter in the West, and
_Boleosoma olmstedi_ in the East are among the commonest species, found
half hidden in the weeds of small brooks, and showing no bright colors,
although the male in the spring has the head, and often the whole body,
jet black.

[Illustration:

  FIG. 248.—Crystal Darter, _Crystallaria asprella_ (Jordan). Wabash
    River.
]

_Crystallaria asprella_, a large species almost transparent, is
occasionally taken in swift currents along the limestone banks of the
Mississippi. Still more transparent is the small sand-darter,
_Ammocrypta pellucida_, which lives in the clearest of waters,
concealing itself by plunging into the sand. Its scales are scantily
developed, as befits a fish that chooses this method of protection, and
in the related _Ammocrypta beani_ of the streams of the Louisiana
pine-woods, the body is almost naked, as also in _Ioa vitrea_, the
glassy darter of the pine-woods of North Carolina.

[Illustration:

  FIG. 249.—Sand-darter, _Ammocrypta clara_ (Jordan & Meek). Des Moines
    River.
]

In the other darters the body is more compressed, the movements less
active, the coloration even more brilliant in the males, which are far
more showy than their dull olivaceous mates.

To _Etheostoma_ nearly half of the species belong, and they form indeed
a royal series of little fishes. Only a few can be noticed here, but all
of them are described in detail and many are figured by Jordan and
Evermann ("Fishes of North and Middle America," Vol. I).

[Illustration:

  FIG. 250.—_Etheostoma jordani_ Gilbert. Chestnut Creek, Verbena, Ala.
]

[Illustration:

  FIG. 251.—Blue-breasted Darter, _Etheostoma camurum_ (Cope), the most
    brilliantly colored of American river fishes. Cumberland Gap, Tenn.
]

Most beautiful of all fresh-water fishes is the blue-breasted darter,
_Etheostoma camurum_, red-blue and olive, with red spots, like a trout.
This species lives in clear streams of the Ohio valley, a region perhaps
to be regarded as the center of abundance of these fishes.

Very similar is the trout-spotted darter, _Etheostoma maculatum_, dusky
and red, with round crimson spots. _Etheostoma rufilineatum_ of the
French Broad is one of the most gaudy of fishes. _Etheostoma australe_
of Chihuahua ranges farthest south of all the darters, and _Etheostoma
boreale_ of Quebec perhaps farthest north, though _Etheostoma iowæ_,
found from Iowa to the Saskatchewan, may dispute this honor. _Etheostoma
cæruleum_, the rainbow darter or soldier-fish, with alternate oblique
bands of blue and scarlet, is doubtless the most familiar of the
brilliantly colored species, as it is the most abundant throughout the
Ohio valley.

_Etheostoma flabellare_, the fan-tailed darter, discovered by Rafinesque
in Kentucky in 1817, was the first species of the series made known to
science. It has no bright colors, but its movements in water are more
active than any of the others, and it is the most hardy in the aquarium.

_Psychromaster tuscumbia_ abounds in the great limestone springs of
northern Alabama, while _Copelandellus quiescens_ swarms in the
black-water brooks which flow into the Dismal Swamp and thence southward
to the Suwanee. It is a little fish not very active, its range going
farther into the southern lowlands than any other. Finally, _Microperca
punctulata_, the least darter, is the smallest of all, with fewest
spines and dullest colors, most specialized in the sense of being least
primitive, but at the same time the most degraded of all the darters.

No fossil forms nearly allied to the darters are on record. The nearest
is perhaps _Mioplosus labracoides_ from the Eocene at Green River,
Wyoming. This elongate fish, a foot long, has the dorsal rays IX-1, 13,
and the anal rays II, 13, its scales finely serrated, and the preopercle
coarsely serrated on the lower limb only. This species, with its
numerous congeners from the Rocky Mountain Eocene, is nearer the true
perch than the darters. Several species related to Perca are also
recorded from the Eocene of England and Germany. A species called
_Lucioperca skorpili_, allied to _Centropomus_, is described from the
Oligocene of Bulgaria, besides several other forms imperfectly
preserved, of still more doubtful affinities.



                              CHAPTER XIX
                      THE BASS AND THEIR RELATIVES


=THE Cardinal-fishes. Apogonidæ.=—The _Apogonidæ_ or cardinal-fishes are
perch-like fishes, mostly of small size, with two distinct short dorsal
fins. They are found in the warm seas, and many of them enter rivers,
some even inhabiting hot springs. Many of the shore species are bright
red in color, usually with black stripes, bands, or spots. Still others,
however, are olive or silvery, and a few in deeper water are
violet-black.

[Illustration:

  FIG. 252.—Cardinal-fish, _Apogon retrosella_ Gill. Mazatlan.
]

The species of _Apogon_ are especially numerous, and in regions where
they are abundant, as in Japan, they are much valued as food. _Apogon
imberbis_, the "king of the mullet," is a common red species of southern
Europe. _Apogon maculatus_ is found in the West Indies. _Apogon
retrosella_ is the pretty "cardenal" of the west coast of Mexico.
_Apogon lineatus_, _semilineatus_ and other species abound in Japan, and
many species occur about the islands of Polynesia. _Epigonus
telescopium_ is a deep-sea fish of the Mediterranean and _Telescopias_
and _Synagrops_ are genera of the depths of the Pacific. _Paramia_ with
strong canines is allied to _Apogon_, and similar in color and habit.

Allied to _Apogon_ are several small groups often taken as distinct
families. The species of _Ambassis_ (_Ambassidæ_) are little fishes of
the rivers and bays of India and Polynesia, resembling small silvery
perch or bass. All these have three anal spines instead of two as in
_Apogon_. Some of these enter rivers and several are recorded from hot
springs. _Scombrops boops_, the mutsu of Japan, is a valued food-fish
found in rather deep water. It is remarkable for its very strong teeth,
although its flesh is feeble and easily torn. A still larger species in
Cuba, _Scombrops oculata_, known as _Escolar chino_, resembles a
barracuda. These fishes with fragile bodies and very strong teeth are
placed by Gill in a separate family (_Scombropidæ_). _Acropoma
japonicum_ is a neat little fish of the Japanese coast, with the vent
placed farther forward than in _Apogon_. It is the type of the
_Acropomidæ_, a small family of the Pacific. _Enoplosus armatus_ is an
Australian fish with high back and fins, with a rather stately
appearance, type of the _Enoplosidæ_. In his last catalogue of families
of fishes Dr. Gill recognizes _Scombropidæ_ and _Acropomidæ_ as distinct
families, but their relationships with _Apogon_ are certainly very
close. Many genera allied to _Apogon_ and _Ambassis_ occur in Australian
rivers. Several fossils referred to _Apogon_ (_Apogon spinosus_, etc.)
occur in the Eocene of Italy and Germany.

=The Anomalopidæ.=—The family of _Anomalopidæ_ is a small group of
deep-sea fishes of uncertain relationship, but perhaps remotely related
to _Apogon_. _Anomalops palpebrata_ is found in Polynesia and has
beneath the eye a large luminous organ unlike anything seen elsewhere
among fishes.

=The Asineopidæ.=—Another family of doubtful relationship is that of
_Asineopidæ_, elsewhere noticed. It is composed of extinct fresh-water
fishes found in the Green River shales. In _Asineops squamifrons_ the
opercles are unarmed, the teeth villiform, and the dorsal fin undivided,
composed of eight or nine spines and twelve to fourteen soft rays. The
anal spines, as in _Apogon_, are two only, and the scales are cycloid.

[Illustration:

  FIG. 253.—Kuromutsu, _Telescopias gilberti_ Jordan & Snyder. Misaki,
    Japan.
]

[Illustration:

  FIG. 254.—_Apogon semilineatus_ Schlegel. Misaki, Japan.
]

[Illustration:

  FIG. 255.—Robalo, _Oxylabrax undecimalis_ (Bloch). Florida.
]

=The Robalos:[13] Oxylabracidæ.=—The family of Robalos (_Oxylabracidæ_
or _Centropomidæ_) is closely related to the _Serranidæ_, differing
among other things in having the conspicuous lateral line extended on
the caudal fin. These are silvery fishes with elongate bodies, large
scales, a pike-like appearance, the first dorsal composed of strong
spines and the second spine of the anal especially large. They are found
in tropical America only, where they are highly valued as food, the
flesh being like that of the striped bass, white, flaky, and of fine
flavor. The common robalo, or snook, _Oxylabrax_ (or _Centropomus_)
_undecimalis_, reaches a weight of fifteen to twenty pounds. It ranges
north as far as Texas. In this species the lateral line is black. The
smaller species, of which several are described, are known as _Robalito_
or _Constantino_.

Footnote 13:

  The European zander is the type of Lacépède's genus _Centropomus_. The
  name _Centropomus_ has been wrongly transferred to the robalo by most
  authors.

=The Sea-bass: Serranidæ.=—The central family of the percoid fishes is
that of the _Serranidæ_, or sea-bass. Of these about 400 species are
recorded, carnivorous fishes found in all warm seas, a few ascending the
fresh waters. In general, the species are characterized by the presence
of twenty-four vertebræ and three anal spines, never more than three.
The fresh-water species are all more or less archaic and show traits
suggesting the _Oxylabracidæ_, _Percidæ_, or _Centrarchidæ_, all of
which are doubtless derived from ancestors of _Serranidæ_. Among the
connecting forms are the perch-like genera _Percichthys_ and _Percilia_
of the rivers of Chile. These species look much like perch, but have
three anal spines, the number of vertebræ being thirty-five.
_Percichthys trucha_ is the common trucha, or trout, of Chilean waters.

_Lateolabrax japonicus_, the susuki, or bass, of Japan, is one of the
most valued food-fishes of the Orient, similar in quality to the robalo,
which it much resembles. This genus and the East Indian _Centrogenys
waigiensis_ approach _Oxylabrax_ in appearance and structure. _Niphon
spinosus_, the ara of Japan, is a very large sea-bass, also of this
type. Close to these bass, marine and fresh water, are the Chinese genus
_Siniperca_ and the Korean genus _Coreoperca_, several species of which
abound in Oriental rivers. In southern Japan is the rare _Bryttosus
kawamebari_, a bass in structure, but very closely resembling the
American sunfish, even to the presence of the bright-edged black
ear-spot. There is reason to believe that from some such form the
_Centrarchidæ_ were derived.

Other bass-like fishes occur in Egypt (_Lates_), Australia
(_Percalates_, etc.), and southern Africa. _Oligorus macquariensis_ is
the great cod of the Australian rivers and _Ctenolates ambiguus_ is the
yellow belly, while _Percalates colonorum_ is everywhere the "perch" in
Australian rivers. The most important member of these transitional types
between perch and sea-bass is the striped bass, or rockfish (_Roccus
lineatus_), of the Atlantic coast of the United States. This large fish,
reaching in extreme cases a weight of 112 pounds, lives in shallow
waters in the sea and ascends the rivers in spring to spawn. It is
olivaceous in color, the sides golden silvery, with narrow black
stripes. About 1880 it was introduced by the United States Fish
Commission into the Sacramento, where it is now very abundant and a fish
of large commercial importance. To the angler the striped bass is always
"a gallant fish and a bold biter," and Genio Scott places it first among
the game-fishes of America.

The white bass (_Roccus chrysops_) is very similar to it, but shorter
and more compressed, reaching a smaller size. This fish is abundant in
the Great Lakes and the upper Mississippi as far south as Arkansas.

The yellow bass (_Morone interrupta_), a coarser and more brassy fish,
replaces it farther south. It is seldom seen above Cincinnati and St.
Louis. The white perch (_Morone americana_) is a little fish of the
Atlantic seaboard, entering the sea, but running up all the rivers,
remaining contentedly landlocked in ponds. It is one of the most
characteristic fishes of the coast from Nova Scotia to Virginia. It is a
good pan fish, takes the hook vigorously, and in a modest way deserves
the good-will of the angler who cannot stray far into the mountains.
Very close to these American bass is the bass, bars, or robalo, of
southern Europe, _Dicentrarchus labrax_, a large olive-colored fish,
excellent as food, living in the sea about the mouths of rivers.

=The Jewfishes.=—In the warm seas are certain bass of immense size,
reaching a length of six feet or more, and being robust in form, a
weight of 500 or 600 pounds. These are dusky green in color,
thick-headed, rough-scaled, with low fins, voracious disposition, and
sluggish movements. In almost all parts of the world these great bass
are called jewfish, but no reason for this name has ever been suggested.
In habit and value the species are much alike, and the jewfish of
California, _Stereolepis gigas_, the prize of the Santa Catalina
anglers, may be taken as the type of them all. Closely related to this
is the Japanese ishinagi, _Megaperca ischinagi_, the jewfish, or
stone-bass, of Japan. Another Japanese jewfish is the Abura bodzu, or
"fat priest," _Ebisus sagamius_. In the West Indies, as also on the west
coast of Mexico, the jewfish, or guasa, is _Promicrops itaiara_. The
black grouper, _Garrupa nigrita_, is the jewfish of Florida. The
European jewfish, more often called _wreckfish_, or stone-bass, is
_Polyprion americanus_, and the equally large _Polyprion oxygeneios_ is
found in Australia, as is also another jewfish, _Glaucosoma hebraicum_,
the last belonging to the _Lutianidæ_. Largest of all these jewfishes is
_Promicrops lanceolata_ of the South Pacific. This huge bass, according
to Dr. Boulenger, sometimes reaches a length of twelve feet.

[Illustration:

  FIG. 256.—White Perch, _Morone americana_ Gmelin. (From life by Dr. R.
    W. Shufeldt; one half natural size.)
]

[Illustration:

  FIG. 257.—Florida Jewfish, _Promicrops itaiara_ (Lichtenstein). St.
    John's River, Fla.
]

Related to the jewfishes are numerous smaller fishes. One of these, the
Spanish-flag of Cuba, _Gonioplectrus hispanus_, is rose-colored, with
golden bands like the flag of Spain itself. Other species referred to
_Acanthistius_ and _Plectropoma_ have, like this, hooked spines on the
lower border of the preopercle.

[Illustration:

  FIG. 258.—_Epinephelus striatus_ (Bloch), Nassau Grouper: _Cherna
    criolla_. Family _Serranidæ_.
]

[Illustration:

  FIG. 259.—John Paw or Speckled Hind, _Epinephelus drummond-hayi_ Goode
    Pensacola.
]

[Illustration:

  FIG. 260.—_Epinephelus morio_ (Cuvier & Valenciennes), Red Grouper, or
    Mero. Family _Serranidæ_.
]

=The Groupers.=—In all warm seas abound species of _Epinephelus_ and
related genera, known as sea-bass, groupers, or merous. They are mostly
large voracious fishes with small scales, pale flesh of fair quality,
and from their abundance they are of large commercial importance. To
English-speaking people these fishes are usually known as grouper, a
corruption of the Portuguese name garrupa. In the West Indies and about
Panama there are very many species, and still others abound in the
Mediterranean, in southern Japan, and throughout Polynesia and the West
Indies. They have very much in common, but differ in size and color,
some being bright red, some gaudily spotted with red or blue, but most
of them are merely mottled green or brown. In many cases individuals
living near shore are olivaceous, and those of the same species in the
depths are bright crimson or scarlet. We name below a few of the most
prominent species. Even a bare list of all of them would take many
pages. _Cephalopholis cruentatus_, the red hind of the Florida Keys, is
one of the smallest and brightest of all of them. _Cephalopholis
fulvus_, the blue-spotted guativere of the Cubans, is called negro-fish,
butter-fish, yellow-fish, or redfish, according to its color, which
varies with the depth. It is red, yellow, or olive, with many round blue
spots. _Epinephelus adscenscionis_, the rock-hind, is spotted everywhere
with orange. _Epinephelus guaza_ is the merou, or giant-bass, of Europe,
a large food-fish of value, rather dull in color. _Epinephelus striatus_
is the Nassau grouper, or _Cherna criolla_, common in the West Indies.
_Epinephelus maculosus_ is the cabrilla of Cuba. _Epinephelus
drummond-hayi_, the speckled hind, umber brown, spotted with lavender,
is one of the handsomest of all the groupers. _Epinephelus morio_, the
red grouper, is the commonest of all these fishes in the American
markets. In Asia the species are equally numerous, _Epinephelus quernus_
of Hawaii and the red _Epinephelus fasciatus_ of Japan and southward
being food-fishes of importance. _Epinephelus merra_, _Epinephelus
gilberti_, and _Epinephelus tauvina_ are among the more common species
of Polynesia. _Epinephelus corallicola_, a species profusely spotted,
abounds in the crevices of coral reefs, while _Cepholopholis argus_ and
_C. leopardus_ are showy fishes of the deeper channels. _Mycteroperca
venenosa_, the yellow-finned grouper, is a large and handsome fish of
the coast of Cuba, the flesh sometimes poisonous; when red in deep water
it is known as the bonaci cardenal. _Mycteroperca bonaci_; the bonaci
arará sells in our markets as black grouper. _Mycteroperca microlepis_
is commonest along our South Atlantic coast, not reaching the West
Indies, and _Mycteroperca rubra_, which is never red, enters the
Mediterranean. _Mycteroperca falcata_ is known in the markets as scamp,
and _Mycteroperca venadorum_ is a giant species from the Venados
Islands, near Mazatlan. _Diploprion bifasciatus_ is a handsome
grouper-like fish with two black cross-bands, found in Japan and India.
_Variola louti_, red, with crimson spots and a forked caudal fin, is one
of the most showy fishes of the equatorial Pacific.

[Illustration:

  FIG. 261.—Red Hind, _Epinephelus adscensionis_ (Osbeck). Puerto Rico.
    (After Evermann.)
]

[Illustration:

  FIG. 262.—Yellow-fin Grouper, _Mycteroperca venenosa_ (Linnæus).
    Havana.
]

The small fishes called Vaca in Cuba belong to the genus _Hypoplectrus_.
Their extraordinary and unexplained variations in color have been
noticed on page 235, Vol. I. The common species—blue, orange, green,
plain, striated, checkered, or striped—bears the name of _Hypoplectrus
unicolor_. (Fig. 264).

=The Serranos.=—In all the species known as jewfish and grouper, as also
in the _Oxylabracidæ_ and most _Centrarchidæ_, the maxillary bone is
divided by a lengthwise suture which sets off a distinct supplemental
maxillary. This bone is wanting in the remaining species of _Serranidæ_,
as it is also in those forms already noticed which are familiarly known
as bass. The species without the supplemental maxillary are in general
smaller in size, the canines are on the sides of the jaws instead of in
front, and there are none of the hinged depressible teeth which are
conspicuous in the groupers. The species are abundant in the Atlantic,
but scarcely any are found in Polynesia, and few in Japan or India.

[Illustration:

  FIG. 263.—_Hypoplectrus unicolor nigricans_ (Poey). Tortugas, Fla.
]

_Serranus cabrilla_ is the Cabrilla of the Mediterranean, a well-known
and excellent food-fish, the original type of the family of _Serranidæ_.
_Serranellus scriba_ is the serran, a very pretty shore-fish of southern
Europe, longer known than any other of the tribe. On the coast of
southern California are also species called Cabrillas, fine, large,
food-fish, bass-like in form, _Paralabrax clathratus_, and other less
common species. The _Cabrillas_ and their relatives are almost all
American, a few straying across to Europe. One of the most important in
the number is the black sea-bass, or black will, of our Atlantic coast,
_Centropristes striatus_. This is a common food-and game-fish, dusky in
color, gamy, and of fine flesh. The squirrel-fishes (_Diplectrum_) and
the many serranos (_Prionodes_) of the tropics, small bright-colored
fishes of the rocks and reefs, must be passed with a word, as also the
small _Paracentropristis_ of the Mediterranean and the fine red
creole-fish of the West Indies, _Paranthias furcifer_. In one species,
_Anyperodon leucogrammicus_ of Polynesia, there are no teeth on the
palatines.

The barber-fish (_Anthias anthias_) of southern Europe, bright red and
with the lateral line running very high, is the type of a numerous group
found at the lowest fishing level in all warm seas. All the species of
this group are bright red, very handsome, and excellent as food.
_Hemianthias vivanus_, known only from the spewings of the red snapper
(_Lutianus aya_) at Pensacola, is one of the most brilliant species,
red, with golden streaks. The genus _Plesiops_ consists of small fishes
almost black in color, with blue spots and other markings, abounding
about the coral reefs. In this genus the lateral line is interrupted and
there is some indication of affinity with the _Opisthognathidæ_.

[Illustration:

  FIG. 264.—Snowy Grouper, _Epinephelus niveatus_ (Cuv. & Val.). Natural
    size: young. (Photograph by Dr. R. W. Shufeldt.)
]

[Illustration:

  FIG. 265.—Soapfish, _Rypticus bistrispinus_ (Mitchill). Virginia.
]

In the soapfishes (_Rypticus_) the supplemental maxillary appears again,
but in these forms the dorsal fin is reduced to two or three spines and
there are none in the anal. _Rypticus saponaceus_, so called from the
smooth or soapy scales, is the best known of the numerous species, which
all belong to tropical America. _Grammistes_, with eight dorsal spines,
is a related form in Polynesia, bright yellow, with numerous black
stripes. Numerous species referred to the _Serranidæ_ occur in the
Eocene and Miocene rocks. Some are related to _Epinephelus_, others to
_Roccus_ and _Lates_. In the Tertiary lignite of Brazil is a species of
_Percichthys_, _Percichthys antiquus_, with _Properca beaumonti_, which
seem to be a primitive form of the bass, allied to _Dicentrarchus_.
_Prolates heberti_ of the Cretaceous, one of the earliest of the series,
has the caudal rounded and is apparently allied to _Lates_, as is also
the heavily armed _Acanus regleysianus_ of the Oligocene. _Smerdis
minutus_, a small fish from the Oligocene, is also related to _Lates_,
which genus with _Roccus_ and _Dicentrarchus_ must represent the most
primitive of existing members of this family. Of both _Smerdis_ and
_Dicentrarchus_ (_Labrax_) numerous species are recorded, mostly from
the Miocene of Europe.

[Illustration:

  FIG. 266.—Flasher, _Lobotes surinamensis_ (Bloch). Virginia.
]

[Illustration:

  FIG. 267.—Catalufa, _Priacanthus arenatus_ Cuv. & Val. Wood's Hole,
    Mass.
]

=The Flashers: Lobotidæ.=—The small family of _Lobotidæ_, flashers, or
triple-tails, closely resembles the _Serranidæ_, but there are no teeth
on vomer or palatines. The three species are robust fishes, of a large
size, of a dark-green color, the front part of the head very short. They
reach a length of about three feet and are good food-fishes. _Lobotes
surinamensis_ comes northward from the West Indies as far as Cape Cod.
_Lobotes pacificus_ is found about Panama. _Lobotes erate_, common in
India, was taken by the writer at Misaki, Japan.

[Illustration:

  FIG. 268.—Bigeye, _Pseudopriacanthus altus_ Gill. Young specimen.
    (From life by Dr. R. W. Shufeldt.)
]

=The Bigeyes: Priacanthidæ.=—The _Catalufas_ or bigeyes (_Priacanthidæ_)
are handsome fishes of the tropics, with short, flattened bodies, rough
scales, large eyes, and bright-red coloration. The mouth is very
oblique, and the anal fin about as large as the dorsal. The commonest
species is _Priacanthus cruentatus_, widely diffused through the Pacific
and also in the West Indies. This is the noted Aweoweo of the Hawaiians,
which used to come into the bays in myriads at the period of death of
royalty. It is still abundant, even after Hawaiian royalty has passed
away.

_Pseudopriacanthus altus_ is a short, very deep-bodied, and very rough
fish, scarlet in color, occasionally taken along our coast, driven
northward by the Gulf Stream. The young fishes are quite unlike the
adult in appearance. Numerous other species of _Priacanthus_ occur in
the Indies and Polynesia.

=The Pentacerotidæ.=—Another family with strong spines and rough scales
is the group of _Pentacerotidæ_. _Histiopterus typus_, the Matodai, is
found in Japan, and is remarkable for its very deep body and very high
spines. Equally remarkable is the Tengudai, _Histiopterus acutirostris_,
also Japanese. _Anoplus banjos_ is a third Japanese species, more common
than the others, and largely taken in the Inland Sea. All these are
eccentric variations from the perch-like type.

=The Snappers: Lutianidæ.=—Scarcely less numerous and varied than the
sea-bass is the great family of _Lutianidæ_, known in America as
snappers or pargos. In these fishes the maxillary slips along its edge
into a sheath formed by the broad preorbital. In the _Serranidæ_ there
is no such sheath. In the _Lutianidæ_ there is no supplemental
maxillary, teeth are present on the vomer and palatines, and in the jaws
there are distinct canines. These fishes of the warm seas are all
carnivorous, voracious, gamy, excellent as food though seldom of fine
grain, the flesh being white and not flaky. About 250 species are known,
and in all warm seas they are abundant.

[Illustration:

  FIG. 269.—Gray Snapper, _Lutianus griseus_ L. Puerto Rico. (After
    Evermann.)
]

To the great genus _Lutianus_ most of the species belong. These are the
snappers of our markets and the pargos of the Spanish-speaking
fishermen. The shore species are green in color, mostly banded, spotted,
or streaked. In deeper water bright-red species are found. One of these,
_Lutianus aya_, the red snapper or pargo guachinango of the Gulf of
Mexico, is, economically speaking, the most important of all these
fishes in the United States. It is a large, rather coarse fish, bright
red in color, and it is taken on long lines on rocky reefs chiefly about
Pensacola and Tampa in Florida, although similar fisheries exist on the
shores of Yucatan and Brazil.

[Illustration:

  FIG. 270.—_Lutianus apodus_ (Walbaum), Schoolmaster or Cají. Family
    _Lutianidæ_.
]

[Illustration:

  FIG. 271.—_Hoplopagrus guntheri_ Gill. Mazatlan.
]

[Illustration:

  FIG. 272.—Lane Snapper or Biajaiba, _Lutianus synagris_ (Linnæus). Key
    West.
]

A related species is the _Lutianus analis_, the mutton snapper or pargo
criollo of the West Indies. This is one of the staple fishes of the
Havana market, always in demand for banquets and festivals, because its
flesh is never unwholesome. The mangrove snapper, or gray-snapper,
_Lutianus griseus_, called in Cuba, Caballerote, is the commonest
species on our coasts. The common name arises from the fact that the
young hide in the mangrove bushes of Florida and Cuba, whence they sally
out in pursuit of sardines and other small fishes. It is a very wary
fish, to be sought with care, hence the name "lawyer," sometimes heard
in Florida. The cubero (_Lutianus cyanopterus_) is a very large snapper,
often rejected as unwholesome, being said to cause the disease known as
ciguatera. Certain snappers in Polynesia have a similar reputation. The
large red mumea, _Lutianus bohar_, is regarded as always poisonous in
Samoa—the most dangerous fish of the islands. _L. leioglossus_ is also
held under suspicion on Tutuila, though other fishes of this type are
regarded as always safe. Other common snappers of Florida and Cuba are
the dog snapper or jocu (_Lutianus jocu_), the schoolmaster or cají
(_Lutianus apodus_), the black-fin snapper or sese de lo alto (_Lutianus
buccanella_), the silk snapper or pargo de lo alto (_Lutianus vivanus_),
the abundant lane snapper or biajaiba (_Lutianus synagris_), and the
mahogany snapper or ojanco (_Lutianus mahogani_). Numerous other species
occur on both coasts of tropical America, and a vastly larger assemblage
is found in the East Indies, some of them ranging northward to Japan.

[Illustration:

  FIG. 273.—Yellow-tail Snapper, _Ocyurus chrysurus_ (Linnæus). Key
    West.
]

[Illustration:

  FIG. 274.—Cachucho, _Etelis oculatus_ (Linnæus). Havana.
]

_Hoplopagrus guntheri_ is a large snapper of the west coast of Mexico,
having very large molar teeth in its jaws besides slit-like nostrils and
other notable peculiarities. From the standpoint of structure this
species, with its eccentric characters—is especially interesting. The
yellow-tail snapper or rabirubia (_Ocyurus chrysurus_) is a handsome and
common fish of the West Indies, with long, deeply forked tail, which
makes it a swifter fish than the others. Another red species is the
diamond snapper or cagon de lo alto, _Rhomboplites aurorubens_. All
these true snappers have the soft fins more or less scaly. In certain
species that swim more freely in deep waters, these fins are naked.
Among them is the Arnillo, _Apsilus dentatus_, a pretty brown fish of
the West Indies, and its analogue in Hawaii, _Apsilus brighami_, red,
with golden cross-bands. _Aprion virescens_, the Uku of Hawaii, is a
large fish of a greenish color and elongate body, widely diffused
throughout Polynesia and one of the best of food-fishes. A related
species is the red voraz (_Aprion macrophthalmus_) of the West Indies.

Most beautiful of all the group are the species of _Etelis_, with the
dorsal fin deeply divided and the head flattened above. These live in
rather deep water about rocky reefs and are fiery red in color. Best
known is the Cuban species, _Etelis oculatus_, the cachucho of the
markets. Equally abundant and equally beautiful is _Etelis carbunculus_
of Polynesia, _Etelis evurus_ of Hawaii, and other species of the
Pacific islands.

[Illustration:

  FIG. 275.—_Xenocys jessiæ_ Jordan & Bollman. Family _Lutianidæ_.
    Galapagos Islands.
]

_Verilus sordidus_, the black escolar of Cuba, has the form of _Etelis_,
but the flesh is very soft and the color violet-black, indicating its
life in very deep water. Numerous small silvery snappers living near the
shore along the coast of western Mexico belong to the genera called
_Xenichthys_, _Xenistius_, and _Xenocys_. _Xenistius californiensis_ is
the commonest of these species, _Xenocys jessiæ_, the largest in size,
with black lines like a striped bass. To the genus _Dentex_ belongs a
large snapper-like fish of the Mediterranean, _Dentex dentex_. Very many
related species occur in the old world, the prettily colored _Nemipterus
virgatus_, the _Itoyori_ of Japan being one of the best known. Another
interesting fish is _Aphareus furcatus_, a handsome, swift fish of the
open seas occasionally taken in Japan and the East Indies. _Glaucosoma
burgeri_ is a large snapper of Japan, and a related species, _Glaucosoma
hebraicum_, is one of the "jewfishes" of Australia. Numerous fossil
forms referred to _Dentex_ occur in the Eocene of Monte Bolca, as also a
fish called _Ctenodentex lackeniensis_ from the Eocene of Belgium.

[Illustration:

  FIG. 276.—_Aphareus furcatus_ (Lacépède). Odawara, Japan. Family
    _Lutianidæ_.
]

[Illustration:

  FIG. 277.—Grunt, _Hæmulon plumieri_ (Bloch). Charleston, S. C.
]

=The Grunts: Hæmulidæ.=—The large family of _Hæmulidæ_, known in America
as grunters or roncos, is represented with the snappers in all tropical
seas. The common names (Spanish, _roncar_, to grunt or snore) refer to
the noise made either with their large pharyngeal teeth or with the
complex air-bladder. These fishes differ from the _Lutianidæ_ mainly in
the feebler detention, there being no canines and no teeth on the vomer.
Most of the American species belong to the genus _Hæmulon_ or red-mouth
grunts, so called from the dash of scarlet at the corner of the mouth.
_Hæmulon plumieri_, the common grunt, or ronco arará, is the most
abundant species, known by the narrow blue stripes across the head. In
the yellow grunt, ronco amarillo (_Hæmulon sciurus_), these stripes
cross the whole body. In the margate-fish, or Jallao (_Hæmulon album_),
the largest of the grunts, there are no stripes at all. Another common
grunt is the black spotted sailor's choice, _Ronco prieto_ (_Hæmulon
parra_), very abundant from Florida southward. Numerous other grunts and
"Tom Tates" are found on both shores of Mexico, all the species of
_Hæmulon_ being confined to America. _Anisotremus_ includes numerous
deep-bodied species with smaller mouth, also all American. _Anisotremus
surinamensis_, the pompon, abundant from Louisiana southward is the
commonest species. _Anisotremus virginicus_, the porkfish or Catalineta,
beautifully striped with black and golden, is very common in the West
Indies. _Plectorhynchus_ of Polynesia and the coasts of Asia contains
numerous large species closely resembling _Anisotremus_, but lacking the
groove at the chin characteristic of _Anisotremus_ and _Hæmulon_. Some
of these are striped or spotted with black in very gaudy fashion.
_Pomadasis_, a genus equally abundant in Asia and America, contains
silvery species of the sandy shores, with the body more elongate and the
spines generally stronger. _Pomadasis crocro_ is the commonest West
Indian species, _Pomadasis hasta_ the best known of the Asiatic forms.
_Gnathodentex aurolineatus_ with golden stripes is common in Polynesia.

[Illustration:

  FIG. 278.—Porkfish, _Anisotremus virginicus_ (Linnæus). Key West.
]

The pigfishes, _Orthopristis_, have the spines feebler and the anal fin
more elongate. Of the many species, American and Mediterranean,
_Orthopristis chrysopterus_ is most familiar, ranging northward to Long
Island, and excellent as a pan fish. _Parapristipoma trilineatum_, the
Isaki of Japan, is equally abundant and very similar to it. Many related
species belong to the Asiatic genera, _Terapon_, _Scolopsis_, _Cæsio_,
etc., sometimes placed in a distinct family as _Teraponidæ_. _Terapon
servus_ enters the streams of Polynesia, and is a very common fish of
the river mouths, taken in Samoa by the boys. _Terapon theraps_ is found
throughout the East Indies. _Terapon richardsoni_ is the Australian
silver perch. _Cæsio_ contains numerous small species, elongate and
brightly colored, largely blue and golden. _Scolopsis_, having a spine
on the preorbital, contains numerous species in the East Indies and
Polynesia. These are often handsomely colored. Among them is the taiva,
_Scolopsis trilineatus_ of Samoa, gray with white streaks and markings
of delicate pattern. A fossil species in the Italian Eocene related to
_Pomadasis_ is _Pomadasis furcatus_. Another, perhaps allied to
_Terapon_, is called _Pelates quindecimalis_.

[Illustration:

  FIG. 279.—The Red Tai of Japan, _Pagrus major_ Schlegel. Family
    _Sparidæ_. (After Kishinouye.)
]

=The Porgies: Sparidæ.=—The great family of _Sparidæ_ or porgies is also
closely related to the _Hæmulidæ_. The most tangible difference rests in
the teeth, which are stronger, and some of those along the side of the
jaw are transformed into large blunt molars, fitted for grinding small
crabs and shells. The name porgy, in Spanish pargo, comes from the Latin
_Pagrus_ and Greek πάγρος, the name from time immemorial of the red
porgy of the Mediterranean, _Pagrus pagrus_. In this species the front
teeth are canine-like, the side teeth molar. It is a fine food-fish,
very handsome, being crimson with blue spots, and in the Mediterranean
it is much esteemed. It also breeds sparingly on our south Atlantic and
Gulf coasts.

[Illustration:

  FIG. 280.—Ebisu, the Fish-god of Japan, bearing a Red Tai. (Sketch by
    Kako Morita.)
]

[Illustration:

  FIG. 281.—Scup, _Stenotomus chrysops_ (Linnæus). Wood's Hole, Mass.
]

[Illustration:

  FIG. 282.—_Calamus bajonado_ (Bloch & Schneider), Jolt-head Porgy. Pez
    de Pluma. Family _Sparidæ_.
]

[Illustration:

  FIG. 283.—Little-head Porgy, _Calamus proridens_ Jordan & Gilbert. Key
    West.
]

Very similar to the porgy is the famous red tai or akadai of Japan
(_Pagrus major_), a fish so highly esteemed as to be, with the rising
sun and the chrysanthemum, a sort of national emblem. In all prints and
images the fish-god Ebisu (Fig. 280), beloved of the Japanese people,
appears with a red tai under his arm. This species, everywhere abundant,
is crimson in color, and the flesh is always tender and excellent. A
similar species is the well-known and abundant "schnapper" of Australia,
_Pagrus unicolor_. Another but smaller tai or porgy, crimson, sprinkled
with blue spots, _Pagrus cardinalis_, occurs in Japan in great
abundance, as also two species similar in character but without red,
known as _Kurodai_ or black tai. These are _Sparus latus_ and _Sparus
berda_. The gilt-head of the Mediterranean, _Sparus aurata_, is very
similar to these Japanese species. _Sparus sarba_ in Australia is the
tarwhine, and _Sparus australis_ the black bream. The numerous species
of _Pagellus_ abound in the Mediterranean. These are smaller in size
than the species of _Pagrus_, red in color and with feebler teeth.
_Monotaxis grandoculis_, known as the "mu," is a widely diffused and
valuable food-fish of the Pacific islands, greenish in color, with pale
cross-bands. Very closely related is also the American scup or fair maid
(_Stenotomus chrysops_), one of our commonest pan fishes. In this genus
and in _Calamus_ the second interhæmal spine is very greatly enlarged,
its concave end formed like a quill-pen and including the posterior end
of the large air-bladder. This arrangement presumably assists in
hearing. Of the penfishes, or pez de pluma, numerous species abound in
tropical America, where they are valued as food. Of these the bajonado
or jolt-head porgy (_Calamus bajonado_) is largest, most common and
dullest in color. _Calamus calamus_ is the saucer-eye porgy, and
_Calamus proridens_, the little-head porgy. _Calamus leucosteus_ is
called white-bone porgy, and the small _Calamus arctifrons_ the
grass-porgy.

The Chopa spina, or pinfish, _Lagodon rhomboides_, is a little porgy
with notched incisors, exceedingly common on our South Atlantic coast.

In some of the porgies the front teeth instead of being canine-like are
compressed and truncate, almost exactly like human incisors. These
species are known as sheepshead, or sargos.

[Illustration:

  FIG. 284.—_Diplodus holbrooki_ Bean. Pensacola.
]

_Diplodus sargus_ and _Diplodus annularis_ are common sargos of the
Mediterranean, silvery, with a black blotch on the back of the tail.
_Diplodus argenteus_ of the West Indies and _Diplodus holbrooki_ of the
Carolina coast are very close to these.

The sheepshead, _Archosargus probatocephalus_, is much the most valuable
fish of this group. The broad body is crossed by about seven black
cross-bands. It is common from Cape Cod to Texas in sandy bays, reaching
rarely a weight of fifteen pounds. Its flesh is most excellent, rich and
tender. The sheepshead is a quiet bottom-fish, but takes the hook
readily and with some spirit. Close to the sheepshead is a smaller
species known as Salema (_Archosargus unimaculatus_), with blue and
golden stripes and a black spot at the shoulder. It abounds in the West
Indies.

[Illustration:

  FIG. 285.—_Archosargus unimaculatus_ (Bloch), Salema, Striped
    Sheepshead. Family _Sparidæ_.
]

On the coast of Japan and throughout Polynesia are numerous species of
_Lethrinus_ and related genera, formed and colored like snappers, but
with molar teeth and the cheek without scales. A common species in Japan
is _Lethrinus richardsoni_.

Fossil species of _Diplodus_, _Sparus_, _Pagrus_, and _Pagellus_ occur
in the Italian Eocene, as also certain extinct genera, _Sparnodus_ and
_Trigonodon_, of similar type. _Sparnodus macrophthalmus_ is abundant in
the Eocene of Monte Bolca.

=The Picarels: Mænidæ.=—The _Mænidæ_, or _Picarels_, are elongate,
gracefully formed fishes, remarkable for the extreme protractility of
the upper jaw. _Spicara smaris_ and several other small species are
found in the Mediterranean. _Emmelichthys_ contains species of larger
size occurring in the West Indies and various parts of the Pacific,
chiefly red and very graceful in form and color. _Emmelichthys
vittatus_, the boga, is occasionally taken in Cuba, _Erythrichthys
schlegeli_ is found in Japan and Hawaii.

[Illustration:

  FIG. 286.—Mojarra, _Xystæma cinereum_ (Walbaum). Key West.
]

=The Mojarras: Gerridæ.=—The _Gerridæ_, or _Mojarras_, have the mouth
equally protractile, but the form of the body is different, being broad,
compressed, and covered with large silvery scales. In some species the
dorsal spines and the third anal spine are very strong, and in some the
second interhæmal is quill-shaped, including the end of the air-bladder,
as in _Calamus_. Most of the species, including all the peculiar ones,
are American. The smallest, _Eucinostomus_, have the quill-shaped
interhæmal and the dorsal and anal spines are very weak. The commonest
species is the silver jenny, or mojarra de Ley, _Eucinostomus gula_,
which ranges from Cape Cod to Rio Janeiro, in the surf along sandy
shores. Equally common is _Eucinostomus californiensis_ of the Pacific
Coast of Mexico, while _Eucinostomus harengulus_ of the West Indies is
also very abundant. _Ulæma lefroyi_ has but two anal spines and the
interhæmal very small. It is common through the West Indies. _Xystæma_,
with the interhæmal spear-shaped and normally formed, is found in Asia
and Polynesia more abundantly than in America, although one species,
_Xystæma cinereum_, the broad shad, or Mojarra blanca, is common on both
shores of tropical America. _Xystæma gigas_ is found in Polynesia, _X.
oyena_ in Japan, and _X. filamentosum_ in Formosa and India. _Xystæma
massalongoi_ is also fossil in the Miocene of Austria. The species of
_Gerres_ have very strong dorsal and anal spines and the back much
elevated. _Gerres plumieri_, the striped mojarra, _Gerres brasiliensis_,
the patao, _Gerres olisthostomus_, the Irish pampano, and _Gerres
rhombeus_ are some of the numerous species found on the Florida coast
and in the West Indies. The family of _Leiognathidæ_, already noticed
(page 287), should stand next to the _Gerridæ_.

[Illustration:

  FIG. 287.—Irish Pampano, _Gerres olisthostomus_ Goode & Bean. Indian
    River, Fla.
]

=The Rudder-fishes: Kyphosidæ.=—The _Kyphosidæ_, called rudder-fishes,
have no molars, the front of the jaws being occupied by incisors, which
are often serrated, loosely attached, and movable. The numerous species
are found in the warm seas and are chiefly herbivorous.

[Illustration:

  FIG. 288.—Chopa or Rudder-fish, _Kyphosus sectatrix_ (Linnæus). Wood's
    Hole, Mass.
]

_Boops boops_ and _Boops salpa_, known as boga and salpa, are elongate
fishes common in the Mediterranean. Other Mediterranean forms are
_Spondyliosoma cantharus_, _Oblata melanura_, etc. _Girella nigricans_
is the greenfish of California, everywhere abundant about rocks to the
south of San Francisco, and of considerable value as food. Almost
exactly like it is the Mejinadai (_Girella punctata_) of Japan. The
best-known members of this group belong to the genus _Kyphosus_.
_Kyphosus sectatrix_ is the rudder-fish, or Chopa blanca, common in the
West Indies and following ships to the northward even as far as Cape
Cod, once even taken at Palermo. It is supposed that it is enticed by
the waste thrown overboard. _Kyphosus elegans_ is found on the west
coast of Mexico, _Kyphosus tahmel_ in the East Indies and Polynesia, and
numerous other species occur in tropical America and along the coasts of
southern Asia. _Sectator ocyurus_ is a more elongate form of
rudder-fish, striped with bright blue and yellow, found in the Pacific.
_Medialuna californiensis_ is the half-moon fish, or medialuna, of
southern California, an excellent food-fish frequently taken on rocky
shores. Numerous related species occur in the Indian seas.

[Illustration:

  FIG. 288_a_.—Blue-green Sunfish, _Apomotis cyanellus_ (Rafinesque).
    Kansas River. (After Kellogg.)
]

Fossil fragments in Europe have been referred to _Boops_,
_Spondyliosoma_, and other genera.



                               CHAPTER XX
                 THE SURMULLETS, THE CROAKERS AND THEIR
                               RELATIVES


[Illustration:

  FIG. 289.—Red Goatfish, or Salmonete, _Pseudupeneus maculatus_ Bloch.
    Family _Mullidæ_ (Surmullets.)
]

=THE Surmullets, or Goatfishes: Mullidæ.=—The _Mullidæ_ (Surmullets) are
shore-fishes of the warm seas, of moderate size, with small mouth, large
scales, and possessing the notable character of two long, unbranched
barbels of firm substance at the chin. The dorsal fins are short, well
separated, the first of six to eight firm spines. There are two anal
spines and the ventral fins, thoracic, are formed of one spine and five
rays. The flesh is white and tender, often of very superior flavor. The
species are carnivorous, feeding chiefly on small animals. They are not
voracious, and predaceous fishes feed freely on them. The coloration is
generally bright, largely red or golden, in nearly all cases with an
under layer, below the scales, of red, which appears when the fish is
scaled or placed in alcohol. The barbels are often bright yellow, and
when the fish swims along the bottom these are carried in advance,
feeling the way. Testing the bottom with their feelers, these fishes
creep over the floor of shallow waters, seeking their food.

The numerous species are all very much alike in form, and the current
genera are separated by details of the arrangement of the teeth. But few
are found outside the tropics.

The surmullet or red mullet of Europe, _Mullus barbatus_, is the most
famous species, placed by the Romans above all other fishes unless it be
the scarus, _Sparisoma cretense_. From the satirical poets we learn that
"enormous prices were paid for a fine fish, and it was the fashion to
bring the fish into the dining-room and exhibit it alive before the
assembled guests, so that they might gloat over the brilliant and
changing colors during the death-agonies." It is red in life, and when
the scales are removed, the color is much brighter.

It is an excellent fish, tender and rich, but nowhere so extravagantly
valued to-day as was formerly the case in Rome. _Mullus surmuletus_ is a
second European species, scarcely different from _Mullus barbatus_.

[Illustration:

  FIG. 290.—Golden Surmullet, _Mullus auratus_ Jordan & Gilbert. Wood's
    Hole, Mass.
]

Equally excellent as food and larger in size are two Polynesian species
known as kumu and munu (_Pseudupeneus porphyreus_ and _Pseudupeneus
bifasciatus_). _Mullus auratus_ is a small surmullet occasionally taken
off our Atlantic coast, but in deeper water than that frequented by the
European species. _Pseudupeneus maculatus_ is the red goatfish or
salmonete, common from Florida to Brazil, as is also the yellow
goatfish, _Pseudupeneus martinicus_, equally valued. Many other species
are found in tropical America, Polynesia, and the Indies and Japan.
Perhaps the most notable are _Upeneus vittatus_, striped with yellow and
with the caudal fin cross-barred and the belly sulphur-yellow, and
_Upeneus arge_, similar, the belly white. The common red and
black-banded "moana" or goatfish of Hawaii is _Pseudupeneus
multifasciatus_.

No fossil _Mullidæ_ are recorded, so far as known to us.

=The Croakers: Sciænidæ.=—The family of _Sciænidæ_ (croakers, roncadors)
is another of the great groups of food-fishes. The species are found on
every sandy shore in warm regions and all of them are large enough to
have value as food, while many have flesh of superior quality. None are
brightly colored, most of the species being nearly plain silvery.

[Illustration:

  FIG. 291.—Spotted Weakfish, _Cynoscion nebulosus_. Virginia.
]

Special characters are the cavernous structure of the bones of the head,
which are full of mucous tracts, the specialization (and occasional
absence) of the air-bladder, and the presence of never more than two
anal spines, one of these being sometimes very large. Most of the
species are marine, all are carnivorous; none inhabit rocky places and
none descend to depths in the sea. At the least specialized extreme of
the family, the mouth is large with strong canines and the species are
slender, swift, and predaceous.

The weakfish or squeteague (_Cynoscion regalis_) is a type of a
multitude of species, large, swift, voracious, but with tender flesh,
which is easily torn. The common weakfish, abundant on our Atlantic
coast, suffers much at the hands of its enemy and associate, the
bluefish. It is one of the best of all our food-fishes. Farther south
the spotted weakfish (_Cynoscion nebulosus_), very incorrectly known as
sea-trout, takes its place, and about New Orleans is especially and
justly prized.

The California "bluefish," _Cynoscion parvipinnis_, is very similar to
these Atlantic species, and there are many other species of _Cynoscion_
on both coasts of tropical America, forming a large part of the best
fish-supply of the various markets of the mainland. On the rocky
islands, as Cuba, and about coral reefs, _Sciænidæ_ are practically
unknown. In the Gulf of California, the totuava, _Cynoscion macdonaldi_,
reaches a weight of 172 pounds, and the stateliest of all, the great
"white sea-bass" of California, _Cynoscion nobilis_, reaches 100 pounds.
In these large species the flesh is much more firm than in the weakfish
and thus bears shipment better. _Cynoscion_ has canines in the upper jaw
only and its species are all American. In the East Indies the genus
_Otolithes_ has strong canines in both jaws. Its numerous species are
very similar in form, habits, and value to those of _Cynoscion_. The
queenfish, _Seriphus politus_, of the California coast, is much like the
others of this series, but smaller and with no canines at all. It is a
very choice fish, as are also the species of _Macrodon_ (_Ancylodon_)
known as pescadillo del red, voracious fishes of both shores of South
America.

_Plagioscion squamosissimus_ and numerous species of _Plagioscion_ and
other genera live in the rivers of South America. A single species, the
river-drum, gaspergou, river sheepshead, or thunder-pumper (_Aplodinotus
grunniens_), is found in streams in North America. This is a large fish
reaching a length of nearly three feet. It is very widely distributed,
from the Great Lakes to Rio Usumacinta in Guatemala, whence it has been
lately received by Dr. Evermann. This species abounds in lakes and
sluggish rivers. The flesh is coarse, and in the Great Lakes it is
rarely eaten, having a rank odor. In Louisiana and Texas it is, however,
regarded as a good food-fish. In this species the lower pharyngeals are
very large and firmly united, while, as in all other _Sciænidæ_, except
the genus _Pogonias_, these bones are separated. In all members of the
family the ear-bones or otoliths are largely developed, often finely
sculptured. The otoliths of the river-drum are known to Wisconsin boys
as "lucky-stones," each having a rude impress of the letter L. The names
roncador, drum, thunder-pumper, croaker, and the like refer to the
grunting noise made by most _Sciænidæ_ in the water, a noise at least
connected with the large and divided air-bladder.

[Illustration:

  FIG. 292.—Mademoiselle, _Bairdiella chrysura_ (Linnæus). Virginia.
]

Numerous silvery species belong to _Larimus_, _Corvula_, _Odontoscion_,
and especially to _Bairdiella_, a genus in which the second anal spine
is unusually strong. The mademoiselle, _Bairdiella chrysura_ is a pretty
fish of our Atlantic coast, excellent as a pan fish. In _Bairdiella
ensifera_ of Panama the second anal spine is enormously large, much as
in a robalo (_Oxylabrax_).

In _Stellifer_ and _Nebris_, the head is soft and spongy. _Stellifer
lanceolatus_ is occasionally taken off South Carolina, and numerous
other species of this and related genera are found farther South.

_Sciænops ocellata_ is the red-drum or channel bass of our South
Atlantic coast, a most important food-fish reaching a weight of
seventy-five pounds. It is well marked by a black ocellus on the base of
the tail. On the coast of Texas, this species, locally called redfish,
exceeds in economic value all other species found in that State.

_Pseudosciæna aquila_, the maigre of southern Europe, is another large
fish, similar in value to the red drum. _Pseudosciæna antarctica_ is the
kingfish of Australia. To _Sciæna_ belong many species, largely Asiatic,
with the mouth inferior, without barbels, the teeth small, and the
convex snout marked with mucous pores. _Sciæna umbra_, the ombre, is the
common European species, _Sciæna saturna_, the black roncador of
California, is much like it. _Sciæna deliciosa_ is one of the most
valued food-fishes of Peru, and _Sciæna argentata_ is valued in Japan.
Species of _Sciæna_ are especially numerous on the coasts of India.

[Illustration:

  FIG. 293.—Red Drum, _Sciænops ocellata_ Linnæus. Texas.
]

_Roncador stearnsi_, the California roncador, is a large fish with a
black ocellus at the base of the pectoral. It has some importance in the
Los Angeles market. The goody, spot, or lafayette (_Leiostomus
xanthurus_) is a small, finely flavored species abundant from Cape Cod
to Texas. Similar to it but inferior is the little roncador (_Genyonemus
lineatus_) of California. The common croaker, _Micropogon undulatus_, is
very abundant on our Eastern coast, and other species known as
verrugatos or white-mouthed drummers replace it farther South.

In _Umbrina_ the chin has a short thick barbel. The species abound in
the tropics, _Umbrina cirrosa_ in the Mediterranean; _Umbrina coroides_
in California, and the handsome _Umbrina roncador_, the yellow-tailed
roncador, in southern California. The kingfish, _Menticirrhus_, differs
in lacking the air-bladder, and lying on the bottom in shallow water the
lower fins are enlarged much as in the darters or gobies. All the
species are American. All are dull-colored and all excellent as food.
_Menticirrhus saxatilis_ is the common kingfish or sea-mink, abundant
from Cape Ann southward, _Menticirrhus americanus_ is the equally common
sand-whiting of Carolina, and _Menticirrhus littoralis_ the
surf-whiting. The California whiting or sand-sucker is _Menticirrhus
undulatus_.

[Illustration:

  FIG. 294.—Yellow-fin Roncador, _Umbrina sinaloæ_ Scofield. Mazatlan.
]

[Illustration:

  FIG. 295.—Kingfish, _Menticirrhus americanus_ (Linnæus). Pensacola.
]

_Pogonias chromis_, the sea-drum, has barbels on the chin and the lower
pharyngeals are enlarged and united as in the river-drum, _Aplodinotus_.
It is a coarse fish common on our Atlantic coasts, a large specimen
taken at St. Augustine weighing 146 pounds. Other species of this
family, belonging to the genus _Eques_, are marked with ribbon-like
stripes of black. _Eques lanceolatus_, known in Cuba as serrana, is the
most ornate of these species, looking like a butterfly-fish or Chætodon.

Several fossil fragments have been doubtfully referred to _Sciæna_,
_Umbrina_, _Pogonias_, and other genera. Otoliths or ear-bones not
clearly identifiable are found from the Miocene on. These structures are
more highly specialized in this group than in any other.

[Illustration:

  FIG. 296.—Drum, _Pogonias chromis_ (Linnæus). Matanzas, Fla.
]

=The Sillaginidæ, etc.=—Allied to the _Sciænidæ_ is the small family of
Kisugos, _Sillaginidæ_, of the coasts of Asia. These are slender,
cylindrical fishes, silvery in color, with a general resemblance to
small _Sciænas_.

_Sillago japonicas_, the kisugo of Japan, is a very abundant species,
valued as food. _Sillago sihama_ ranges from Japan to Abyssinia.

A number of small families, mostly Asiatic, may be appended to the
percoid series, with which they agree in general characters, especially
in the normal structure of the shoulder-girdle and in the insertion of
the pectoral and ventral fins.

The _Lactariidæ_ constitute a small family of the East Indies, allied to
the _Sciænidæ_, but with three anal spines. The mouth is armed with
strong teeth. _Lactarius lactarius_ is a food-fish of India.

The _Nandidæ_ are small spiny-rayed fishes of the East Indian streams,
without pseudobranchiæ.

The _Polycentridæ_ are small fresh-water perch-like fishes of the
streams of South America, without lateral line and with many anal
spines.

=The Jawfishes: Opisthognathidæ, etc.=—The _Pseudochromipidæ_ are
marine-fishes of the tropics with the lateral line interrupted, and with
a single dorsal. They bear some resemblance to _Plesiops_ and other
aberrant _Serranidæ_.

[Illustration:

  FIG. 297.—_Gnathypops evermanni_ Jordan & Snyder. Misaki, Japan.
]

[Illustration:

  FIG. 298.—Jawfish, _Opisthognathus macrognathus_ Poey. Tortugas, Fla.
]

Very close to these are the _Opisthognathidæ_ or jawfishes with a single
lateral line and the mouth very large. In certain species of
_Opisthognathus_, the maxillary, long and curved, extends far behind the
head. The few species are found in warm seas, but always very sparingly.
Some of them are handsomely colored.

=The Stone-wall Perch: Oplegnathidæ.=—A singular group evidently allied
to the _Hæmulidæ_ is the family of _Oplegnathidæ_. In these fishes the
teeth are grown together to form a bony beak like the jaw of a turtle.
Except for this character, the species are very similar to ordinary
grunts. While the mouth resembles that of the parrot-fish, it is
structurally different and must have been independently developed.
_Oplegnathus punctatus_, the "stonewall perch" (ishigakidai), is common
in Japan, as is also the banded _Oplegnathus fasciatus_. Other species
are found in Australia and Chile.

[Illustration:

  FIG. 299.—_Opisthognathus nigromarginatus._ India. (After Day.)
]

=The Swallowers: Chiasmodontidæ.=—The family of swallowers
_Chiasmodontidæ_, is made up of a few deep-sea fishes of soft flesh and
feeble spines, the opercular apparatus much reduced. The ventrals are
post-thoracic, the rays I, 5, facts which point to some affinity with
the _Opisthognathidæ_, although Boulenger places these fishes among the
_Percesoces_. _Chiasmodon niger_, the black swallower of the
mid-Atlantic, has exceedingly long teeth and the whole body so
distensible that it can swallow fishes of many times its own size.
According to Gill:

[Illustration:

  FIG. 300.—Black Swallower, _Chiasmodon niger_ Johnson, containing a
    fish larger than itself. Le Have Bank.
]

"It espies a fish many times larger than itself, but which,
nevertheless, may be managed; it darts upon it, seizes it by the tail
and gradually climbs over it with its jaws, first using one and then the
other; as the captive is taken in the stomach and integuments stretch
out, and at last the entire fish is passed through the mouth and into
the stomach, and the distended belly appears as a great bag, projecting
out far backwards and forwards, over which is the swallower with the
ventrals dislocated and far away from their normal place. The walls of
the stomach and belly have been so stretched that they are transparent,
and the species of the fish can be discerned within. But such rapacity
is more than the captor itself can stand. At length decomposition sets
in, the swallower is forced belly upwards, and the imprisoned gas, as in
a balloon, takes it upwards from the depths to the surface of the ocean,
and there, perchance, it may be found and picked up, to be taken home
for a wonder, as it is really. Thus have at least three specimens found
their way into museums—one being in the United States National Museum—
and in each the fish in the stomach has been about twice as long, and
stouter in proportion, than the swallower—six to twelve times bulkier!
Its true habitat seems to be at a depth of about 1,500 fathoms."

Allied to this family is the little group of _Champsodontidæ_ of Japan
and the East Indies. _Champsodon vorax_ looks like a young
_Uranoscopus_. The body is covered with numerous lateral lines and
cross-lines.

=The Malacanthidæ.=—The _Malacanthidæ_ are elongate fishes, rather
handsomely colored, with a strong canine on the premaxillary behind.
_Malacanthus plumieri_, the matajuelo blanco, a slender fish of a
creamy-brown color, is common in the West Indies. Other species are
found in Polynesia, the most notable being _Malacanthus_ (or _Oceanops_)
_lativittatus_, a large fish of a brilliant sky-blue, with a jet-black
lateral band. In Samoa this species is called gatasami, the "eye of the
sea."

=The Blanquillos: Latilidæ.=—The _Latilidæ_, or blanquillos, have also
an enlarged posterior canine, but the body is deeper and the flesh more
firm. The species reach a considerable size and are valued as food.
_Lopholotilus chamæleonticeps_ is the famous tilefish dredged in the
depths under the Gulf Stream. It is a fish of remarkable beauty, red and
golden. This species, Professor Gill writes, "was unknown until 1879,
when specimens were brought by fishermen to Boston from a previously
unexplored bank about eighty miles southeast of No Man's Land, Mass. In
the fall of 1880 it was found to be extremely abundant everywhere off
the coast of southern New England at a depth of from seventy-five to two
hundred and fifty fathoms. The form of the species is more compressed,
and higher, than in most of the family, and what especially
distinguishes it is the development of a compressed, 'fleshy, fin-like
appendage over the back part of the head and nape, reminding one of the
adipose fin of the salmonids and catfishes.' It is especially notable,
too, for the brilliancy of its colors, as well as for its size, being by
far larger than any other member of its family. A weight of fifty pounds
or more is, or rather, one might say, was frequently attained by it,
although such was very far above the average, that being little over ten
pounds. In the reach of water referred to, it could once be found
abundantly at any time, and caught by hook and line. After a severe gale
in March, 1882, millions of tilefish could be seen, or calculated for,
on the surface of the water for a distance of about three hundred miles
from north to south, and fifty miles from east to west. It has been
calculated by Capt. Collins that as many as one thousand four hundred
and thirty-eight millions were scattered over the surface. This would
have allowed about two hundred and twenty-eight pounds to every man,
woman and child of the fifty million inhabitants of the United States!
On trying at their former habitat the next fall, as well as all
successive years to the present time, not a single specimen could be
found where formerly it was so numerous. We have thus a case of a
catastrophe which, as far as has been observed, caused complete
annihilation of an abundant animal in a very limited period. Whether the
grounds it formerly held will be reoccupied subsequently by the progeny
of a protected colony remains to be seen, but it is scarcely probable
that the entire species has been exterminated." It is now certain that
the species is not extinct.

_Caulolatilus princeps_ is the blanquillo or "whitefish" of southern
California, a large handsome fish formed like a dolphin, of purplish,
olivaceous color and excellent flesh. Other species of _Caulolatilus_
are found in the West Indies. _Latilus_ _japonicus_ is the amadai or
sweet perch of Japan, an excellent food-fish of a bright crimson color.

The _Pinguipedidæ_ of Chile resemble the _Latilidæ_, having also the
enlarged premaxillary tooth. The ventrals are, however, thickened and
placed farther forward.

=The Bandfishes: Cepolidæ.=—The small family of _Cepolidæ_, or
bandfishes, resemble the _Latilidæ_ somewhat and are probably related to
them. The head is normally formed, the ventral fins are thoracic, with a
spine and five rays, but the body is drawn out into a long eel-like
form, the many-rayed dorsal and anal fins meeting around the tail. The
few species are crimson in color with small scales. They are used as
food, but the flesh is dry and the bones are stiff and numerous. _Cepola
tænia_ is common in the Mediterranean, and _Acanthocepola krusensterni_
abounds in the bays of southern Japan.

=The Cirrhitidæ.=—The species of the family _Cirrhitidæ_ strongly
resemble the smaller _Serranidæ_ and even _Serranus_ itself, but the
lower rays of the pectoral fins are enlarged and are undivided, as in
the sea-scorpions and some sculpins. In these fishes, however, the bony
stay, which characterizes _Scorpænidæ_ and _Cottidæ_, is wholly absent.
It is, however, considered possible that this interesting family
represents the point of separation at which the mail-cheeked fishes
become differentiated from the typical perch-like forms. _Goniistius
zonatus_, the _takanohadai_, is a valuable food-fish of Japan, marked by
black cross-bands. _Paracirrhites forsteri_ and other species of
_Cirrhitus_ and _Paracirrhites_ are very pretty fishes of the coral
reefs, abundant in the markets of Honolulu, the spotted _Cirrhitus
marmoratus_ being the most widely diffused of these. Only one species of
this family, _Cirrhitus rivulatus_, a large fish, green, with blue
markings, is found in American waters. It frequents the rocky shores of
the west coast of Mexico.

Allied to the _Cirrhitidæ_ is the small family of _Latrididæ_, with a
long dorsal fin deeply divided, and the lower rays of the pectoral
similarly modified. _Latris hecateia_ is called the "trumpeter" in
Australian waters. It is one of the best food-fishes of Australia,
reaching a weight of sixty to eighty pounds.

Another small family showing the same peculiar structure of the pectoral
fin is that of the _Aplodactylidæ_. The species of _Aplodactylus_ live
on the coasts of Chile and Australia. They are herbivorous fishes, with
flat, tricuspid teeth, and except for their pectoral fins are very
similar to the _Kyphosidæ_.

[Illustration:

  FIG. 301.—_Cirrhitus rivulatus_ Valenciennes. Mazatlan.
]

=The Sandfishes: Trichodontidæ.=—In the neighborhood of the _Latrididæ_,
Dr. Boulenger places the _Trichodontidæ_ or sandfishes, small,
scaleless, silvery fishes of the northern Pacific. These are much
compressed in body, with very oblique mouths, with fringed lips and, as
befits their northern habitat, with a much increased number of vertebræ.
They bury themselves in sand under the surf, and the two species,
_Trichodon trichodon_ and _Arctoscopus japonicus_, range very widely in
the regions washed by the Japan current. These species bear a strong
resemblance to the star-gazers (_Uranoscopus_), but this likeness seems
to be superficial only.

[Illustration:

  FIG. 302.—Sandfish, _Trichodon trichodon_ (Tilesius). Shumagin
    Islands, Alaska.
]



                              CHAPTER XXI
                       LABYRINTHICI AND HOLCONOTI


=THE Labyrinthine Fishes.=—An offshoot of the _Percomorphi_ is the group
of _Labyrinthici_, composed of perch-like fishes which have a very
peculiar structure to the pharyngeal bones and respiratory apparatus.
This feature is thus described by Dr. Gill:

"The upper elements of one of the pairs of gill-bearing arches are
peculiarly modified. The elements in question (called branchihyal) of
each side, instead of being straight and solid, as in most fishes, are
excessively developed and provided with several thin plates or folds,
erect from the surface of the bones and the roof of the skull, to which
the bones are attached. These plates, by their intersection, form
chambers, and are lined with a vascular membrane, which is supplied with
large blood-vessels. It was formerly supposed that the chambers referred
to had the office of receiving and retaining supplies of water which
should trickle down and keep the gills moist; such was supposed to be an
adaptation for the sustentation of life out of the water. The
experiments of Surgeon Day, however, throw doubt upon this alleged
function, and tend to show: (1) that these fishes died when deprived of
access to atmospheric air, not from any deleterious properties either in
the water or in the apparatus used, but from being unable to subsist on
air obtained solely from the water, aerial respiration being
indispensable; (2) that they can live in moisture out of the water for
lengthened periods, and for a short, but variable period in water only;
and (3) that the cavity or receptacle does not contain water, but has a
moist secreting surface, in which air is retained for the purpose of
respiration. It seems probable that the air, after having been supplied
for aerial respiration, is ejected by the mouth, and not swallowed to be
discharged per anum. In fine, the two respiratory factors of the
branchial apparatus have independent functions: (1) the labyrinthiform,
or branchihyal portion, being a special modification for the respiration
of atmospheric air, and (2) the gill filaments discharging their normal
function. If, however, the fish is kept in water and prevented from
coming to the surface to swallow the atmospheric air, the labyrinthiform
apparatus becomes filled with water which cannot be discharged, owing to
its almost non-contractile powers. There is thus no means of emptying
it, and the water probably becomes carbonized and unfit for oxygenizing
the blood, so that the whole of the respiration is thus thrown on the
branchiæ. This will account for the fact that when the fish is in a
state of quiescence, it lives much longer than when excited, whilst the
sluggishness sometimes evinced may be due to poisoned or carbonized
blood."

Four families of labyrinth-gilled fishes are recognized by Professor
Gill; and to these we may append a fifth, which, however, lacks the
elaborate structures mentioned above and which shows other evidences of
degeneration.

=The Climbing-perches: Anabantidæ.=—The family of _Anabantidæ_,
according to Gill, "includes those species which have the mouth of
moderate size and teeth on the palate (either on the vomer alone, or on
both the vomer and palatine bones). To the family belongs the celebrated
climbing-fish.

[Illustration:

  FIG. 303.—The Climbing Perch, _Anabas scandens_ Linnæus. Opercle cut
    away to show the gill-labyrinth.
]

"The climbing-fish (_Anabas scandens_) is especially noteworthy for the
movability of the suboperculum. The operculum is serrated. The color is
reddish olive, with a blackish spot at the base of the caudal fin; the
head, below the level of the eye, grayish, but relieved by an olive band
running from the angle of the mouth to the angle of the preoperculum,
and with a black spot on the membrane behind the hindermost spines of
the operculum.

"The climbing-fish was first made known in a memoir, printed in 1797, by
Daldorf, a lieutenant in the service of the Danish East India Company at
Tranquebar. Daldorf called it _Perca scandens_, and affirmed that he
himself had taken one of these fishes, clinging by the spine of its
operculum in a slit in the bark of a palm (_Borassus flabelliformis_)
which grew near a pond. He also described its mode of progression; and
his observations were substantially repeated by the Rev. Mr. John, a
missionary resident in the same country. His positive evidence was,
however, called into question by those who doubted on account of
hypothetical considerations. Even in popular works not generally prone
to even a judicious skepticism, the accounts were stigmatized as
unworthy of belief. We have, however, in answer to such doubts, too
specific information to longer distrust the reliability of the previous
reports.

"Mr. Rungasawmy Moodeliar, a native assistant of Capt. Jesse Mitchell of
the Madras Government Central Museum, communicated to his superior the
statement that 'this fish inhabits tanks or pools of water, and is
called _Panai feri_, i.e., the fish that climbs palmyra-trees. When
there are palmyra-trees growing by the side of a tank or pool, when
heavy rain falls and the water runs profusely down their trunks, this
fish, by means of its opercula, which move unlike those of other fishes,
crawls up the tree sideways (i.e., inclining to the sides considerably
from the vertical) to a height of from five to seven feet, and then
drops down. Should this fish be thrown upon the ground, it runs or
proceeds rapidly along in the same manner (sideways) as long as the
mucus on it remains.'

"These movements are effected by the opercula, which, it will be
remembered, are unusually mobile in this species; they can, according to
Captain Mitchell (and I have verified the statement), be raised or
turned outwards to nearly a right angle with the body, and when in that
position, the suboperculum distends a little, and it appears that it is
chiefly by the spines of this latter piece that the fish takes a
purchase on the tree or ground. 'I have,' says Captain Mitchell,
'ascertained by experiment that the mere closing of the operculum, when
the spines are in contact with any surface, even common glass, pulls an
ordinary-sized fish forwards about half an inch,' but it is probable
that additional force is supplied by the caudal and anal fins, both of
which, it is said, are put in use when climbing or advancing on the
ground; the motion, in fact, is described as a wriggling one.

"The climbing-fish seems to manifest an inclination to ascend streams
against the current, and we can now understand how, during rain, the
water will flow down the trunk of a tree, and the climbing-fish, taking
advantage of this, will ascend against the down-flow by means of the
mechanism already described, and by which it is enabled to reach a
considerable distance up the trunk." (Gill.)

=The Gouramis: Osphromenidæ.=—"The _Osphromenidæ_ are fishes with a
mouth of small size, and destitute of teeth on the palate. To this
family belongs the gourami, whose praises have been so often sung, and
which has been the subject of many efforts for acclimatization in France
and elsewhere by the French.

"The gourami (_Osphromenus goramy_) has an oblong, oval form, and, when
mature, the color is nearly uniform, but in the young there are black
bands across the body, and also a blackish spot at the base of the
pectoral fin. The gourami, if we can credit reports, occasionally
reaches a gigantic size, for it is claimed that it sometimes attains a
length of 6 feet, and weighs 150 pounds, but if this is true, the size
is at least exceptional, and one of 20 pounds is a very large fish;
indeed, they are considered very large if they weigh as much as 12 or 14
pounds, in which case they measure about 2 feet in length.

"The countries in which the gourami is most at home lie in the
intertropical belt. The fish is assiduous in the care of its young, and
prepares a nest for the reception of eggs. The bottom selected is muddy,
the depth variable within a narrow area, that is, in one place about a
yard, and near by several yards deep.

"They prefer to use, for the nests, tufts of a peculiar grass (_Panicum
jumentorum_) which grows on the surface of the water, and whose floating
roots, rising and falling with the movements of the water, form natural
galleries, under which the fish can conceal themselves. In one of the
corners of the pond, among the plants which grow there, the gouramis
attach their nest, which is of a nearly spherical form, and composed of
plants and mud, and considerably resembles in form those of some birds.

"The gourami is omnivorous, taking at times flesh, fish, frogs, insects,
worms, and many kinds of vegetables; and on account of its omnivorous
habit, it has been called by the French colonists of Mauritius _porc des
rivières_, or 'water-pig.' It is, however, essentially a vegetarian, and
its adaptation for this diet is indicated by the extremely elongated
intestinal canal, which is many times folded upon itself. It is said to
be especially fond of the leaves of several araceous plants. Its flesh
is, according to several authors, of a light-yellow straw-color, firm
and easy of digestion. They vary in quality with the nature of the
waters inhabited, those taken from a rocky river being much superior to
those from muddy ponds; but those dwelling at the mouth of rivers, where
the water is to some extent brackish, are the best of all. Again, they
vary with age; and the large, overgrown fishes are much less esteemed
than the small ones. They are in their prime when three years old. Dr.
Vinson says the flavor is somewhat like that of carp; and, if this is
so, we may entertain some skepticism as to its superiority; but the
unanimous testimony in favor of its excellence naturally leads to the
belief that the comparison is unfair to the gourami.

"Numerous attempts have been made by the French to introduce the gourami
into their country, as well as into several of their provinces; and for
a number of years consignments of the eggs, or the young, or adult fish,
were made. Although at least partially successful, the fish has never
been domiciliated in the Republic, and, indeed, it could not be
reasonably expected that it would be, knowing, as we do, its
sensitiveness to cold and the climates under which it thrives.

"The fish of paradise (_Macropodus viridi-auratus_) is a species
remarkable for its beauty and the extension of its fins, and especially
of the ventrals, which has obtained for it the generic name
_Macropodus_. To some extent this species has also been made the subject
of fish-culture, but with reference to its beauty and exhibition in
aquaria and ponds, like the goldfish, rather than for its food
qualities.

"The only other fish of the family that needs mention is the
fighting-fish (_Betta pugnax_). It is cultivated by the natives of Siam,
and a special race seems to have been the result of such cultivation.
The fishes are kept in glasses of water and fed, among other things,
with the larvæ of mosquitoes or other aquatic insects. 'The Siamese are
as infatuated with the combats of these fishes as the Malays are with
their cock-fights, and stake on the issue considerable sums, and
sometimes their own persons and families. The license to exhibit
fish-fights is farmed, and brings a considerable annual revenue to the
king of Siam. The species abounds in the rivulets at the foot of the
hills of Penang. The inhabitants name it 'pla-kat,' or the
'fighting-fish.'"

The _Helostomidæ_ are herbivorous, with movable teeth on the lips and
with long intestines. _Helostoma temmincki_ lives in the rivers of Java,
Borneo, and Sumatra.

The _Luciocephalidæ_ of East Indian rivers have the suprabranchial organ
small, formed of two gill-arches dilated by a membrane. In these species
there are no spines in the dorsal and anal, while in the _Anabantidæ_
and _Osphromenidæ_ numerous spines are developed both in the dorsal and
anal. _Luciocephalus pulcher_ indicates a transition toward the
_Ophicephalidæ_.

=The Snake-head Mullets: Ophicephalidæ.=—The family of _Ophicephalidæ_,
snake-head mullets, or China-fishes, placed among the _Percesoces_ by
Cope and Boulenger, seems to us nearer the Labyrinthine fishes, of which
it is perhaps a degenerate descendant. The body is long, cylindrical,
covered with firm scales which on the head are often larger and
shield-like. The mouth is large, the head pike-like, and the habit
carnivorous and voracious. There are no spines in any of the fins, but
the thoracic position of the ventrals indicates affinity with perch-like
forms and the absence of ventral spines seems rather a feature of
degradation, the more so as in one genus (_Channa_) the ventrals are
wanting altogether. The numerous species are found in the rivers of
southern China and India, crossing to Formosa and to Africa. They are
extremely tenacious of life, and are carried alive by the Chinese to San
Francisco and to Hawaii, where they are now naturalized, being known as
"China-fishes."

[Illustration:

  FIG. 304.—_Channa formosana_ Jordan & Evermann. Streams of Formosa.
]

[Illustration:

  FIG. 305.—Snake-headed China-fish, _Ophicephalus barca_. India. (After
    Day.)
]

These fishes have no special organ for holding water on the gills, but
the gill space may be partly closed by a membrane. According to Dr.
Günther, these fishes are "able to survive drought living in semi-fluid
mud or lying in a torpid state below the hard-baked crusts of the bottom
of a tank from which every drop of water has disappeared. Respiration is
probably entirely suspended during the state of torpidity, but whilst
the mud is still soft enough to allow them to come to the surface, they
rise at intervals to take in a quantity of air, by means of which their
blood is oxygenized. This habit has been observed in some species to
continue also to the period of the year in which the fish lives in
normal water, and individuals which are kept in a basin and prevented
from coming to the surface and renewing the air for respiratory purposes
are suffocated. The particular manner in which the accessory branchial
cavity participates in respiratory functions is not known. It is a
simple cavity, without an accessory branchial organ, the opening of
which is partly closed by a fold of the mucous membrane."

_Ophicephalus striatus_ is the most widely diffused species in China,
India, and the Philippines, living in grassy swamps and biting at any
bait from a live frog to an artificial salmon-fly. It has been
introduced into Hawaii. _Ophicephalus marulius_ is another very common
species, as is also _Channa orientalis_, known by the absence of ventral
fins.

=Suborder Holconoti, the Surf-fishes.=—Another offshoot from the
perch-like forms is the small suborder of _Holconoti_ (ὅλκος, furrow;
νῶτος, back). It contains fishes percoid in appearance, with much in
common with the _Gerridæ_ and _Sparidæ_, but with certain striking
characteristics not possessed by any perch or bass. All the species are
viviparous, bringing forth their young alive, these being in small
number and born at an advanced stage of development. The lower
pharyngeals are solidly united, as in the _Labridæ_, a group which these
fishes resemble in scarcely any other respects. The soft dorsal and anal
are formed of many fine rays, the anal being peculiarly modified in the
male sex. The nostrils, ventral fins, and shoulder-girdle have the
structure normal among perch-like fishes, and the dorsal furrow, which
suggested to Agassiz the name of _Holconoti_, is also found among
various perch-like forms.

[Illustration:

  FIG. 306.—White Surf-fish, viviparous, with young, _Cymatogaster
    aggregatus_ Gibbons. San Francisco.
]

[Illustration:

  FIG. 307.—Fresh-water Viviparous Perch, _Hysterocarpus traski_
    Gibbons. Sacramento River.
]

[Illustration:

  FIG. 308.—_Hypsurus caryi_ (Agassiz). Monterey.
]

=The Embiotocidæ.=—The group contains a single family, the
_Embiotocidæ_, or surf-fishes. All but two of the species are confined
to California, these two living in Japan. The species are relatively
small fishes, from five inches to eighteen inches in length, with rather
large, usually silvery scales, small mouths and small teeth. They feed
mainly on crustaceans, two or three species being herbivorous. With two
exceptions, they inhabit the shallow waters on sandy beaches, where they
bring forth their young. They can be readily taken in nets in the surf.
As food-fishes they are rather inferior, the flesh being somewhat watery
and with little flavor. Many are dried by the Chinese. The two
exceptions in distribution are _Hysterocarpus traski_, which lives
exclusively in fresh waters, being confined to the lowlands of the
Sacramento Basin, and _Zalembius rosaceus_, which descends to
considerable depths in the sea. In _Hysterocarpus_ the spinous dorsal is
very greatly developed, seventeen stout spines being present, the others
having but eight to eleven and these very slender.

[Illustration:

  FIG. 309.—White Surf-fish, _Damalichthys argyrosomus_ (Girard).
    British Columbia.
]

[Illustration:

  FIG. 310.—Thick-lipped Surf-fish, _Rhacochilus toxotes_ Agassiz.
    Monterey, Cal.
]

[Illustration:

  FIG. 311.—Silver Surf-fish (viviparous), _Hypocritichthys analis_
    (Agassiz). Monterey.
]

The details of structure vary greatly among the different species, for
which reason almost every species has been properly made the type of a
distinct genus. The two species found in Japan are _Ditrema temmincki_
and _Neoditrema ransonneti_. In the latter species the female is always
toothless. Close to _Ditrema_ is the blue surf-fish of California,
_Embiotoca jacksoni_, the first discovered and perhaps the commonest
species. _Tæniotoca lateralis_ is remarkable for its bright coloration,
greenish, with orange stripes. _Hypsurus caryi_, still brighter in
color, orange, green and black, has the abdominal region very long.
_Phanerodon furcatus_ and _P. atripes_ are dull silvery in color, as in
_Damalichthys argyrosomus_, the white surf-fish, which ranges northward
to Vancouver Island, and is remarkable for the extraordinary size of its
lower pharyngeals. _Holconotus rhodoterus_ is a large, rosy species, and
_Amphistichus argenteus_ a large species with dull yellowish
cross-bands. _Rhachochilus toxotes_ is the largest species in the family
and the one most valued as food. It is notable for its thick, drooping,
ragged lips. _Hyperprosopon arcuatus_, the wall-eye surf-fish, is
brilliantly silvery, with very large eyes. _H. agassizi_ closely
resembles it, as does also the dwarf species, _Hypocritichthys analis_,
to which the Japanese _Neoditrema ransonneti_ is very nearly related.
The other species are all small. _Abeona minima_ and _A. aurora_ feed on
seaweed. _Brachyistius frenatus_ is the smallest of all, orange-red in
color, while its relative, _Zalembius rosaceus_, is handsomest of all,
rose-red with a black lateral spot. _Cymatogaster aggregatus_, the
surf-shiner, is a little fish, excessively common along the California
coast, and from its abundance it has been selected by Dr. Eigenmann as
the basis of his studies of these fishes. In this species the male shows
golden and black markings, which are wanting in the silvery female, and
the anterior rays of the anal are thickened or otherwise modified.

No fossil embiotocoids are recorded.

The viviparity of the Embiotocidæ was first made known by Dr. A. C.
Jackson in 1863 in a letter to Professor Agassiz. From this letter we
make the following extracts:

"A few days, perhaps a week, after the four trials, and on the _7th of
June_, I rose early in the morning for the purpose of taking a mess of
fish for breakfast, pulled to the usual place, baited with crabs, and
commenced fishing, the wind blowing too strong for profitable angling;
nevertheless on the first and second casts I fastened the two fishes,
male and female, that I write about, and such were their liveliness and
strength that they endangered my slight trout rod. I, however, succeeded
in bagging both, though in half an hour's subsequent work I got not even
a nibble from either this or any other species of fish. I determined to
change the bait, to put upon my hook a portion of the fish already
caught, and cut for that purpose into the larger of the two fish caught.
I intended to take a piece from the thin part of the belly, when what
was my surprise to see coming from the opening thus made _a small live
fish_. This I at first supposed to be prey which this fish had
swallowed, but on further opening the fish I was vastly astonished to
find next to the back of the fish and slightly attached to it _a long
very light violet bag, so clear and so transparent that I could already
distinguish through it the shape, color, and formation of a multitude_
of small fish (_all facsimiles of each other_), with which it was well
filled. I took it on board (we were occupying a small vessel which we
had purchased for surveying purposes). When I opened the bag, I took
therefrom _eighteen_ more of the young fish, precisely like in size,
shape, and color the first I had accidentally extracted. The _mother was
very large round her center and of a very dark-brown color, approaching
about the back and on the fins a black color, and a remarkably vigorous
fish_. The young which I took from her were in shape, save as to
rotundity, perfect miniatures of the mother, formed like her, and of the
same general proportions, except that the old one was (probably owing to
her pregnancy) much broader and wider between the top of the dorsal and
the ventral fins in proportion to her length than the young were. _As to
color, they were in all respects like the mother, though the shades were
many degrees lighter._ Indeed, they were in all respects like their
mother and like each other, the same peculiar mouth, the same position
and shape of the fins, and the same eyes and gills, and there cannot
remain in the mind of any one who sees the fish in the same state that I
did a single doubt that these young were the offspring of the fish from
whose body I took them, and _that this species of fish gives birth to
her young alive and perfectly formed, and adapted to seeking its own
livelihood in the water. The number of young in the bag was nineteen_ (I
fear I misstated the number in my former letter), _and every one as
brisk and lively and as much at home in a bucket of salt water as if
they had been for months accustomed to the water_. The male fish that
was caught was not quite as large as the female, either in length or
circumference, and altogether a more slim fish. I think we may
reasonably expect to receive the specimens by the first of December. But
I can hardly hope to get satisfactory specimens of the fish as I found
it, with young well grown, before the return of the same season, viz.,
June. By that time I trust the facts will be fully decided, and the
results, as important as they may be, fully appreciated."

Dr. Jackson's specimens came from Sausalito Bay, near San Francisco.
Soon after the publication of this letter a similar discovery was made
independently by Dr. William P. Gibbons, of Alameda. Still other
specimens were made known in 1854 by Dr. Charles Girard, these having
been collected in connection with the United States Pacific Railroad
Surveys. The species first examined by Dr. Jackson was named by Agassiz
_Embiotoca jacksoni_.

In Professor Agassiz's comments on Dr. Jackson's discovery he makes the
following observations (_Amer. Jour. Science and Arts_, 1854):

"The female genital apparatus in the state of pregnancy consists of a
large bag the appearance of which in the living animal has been
described by Mr. Jackson. Upon the surface of it large vascular
ramifications are seen, and it is subdivided internally into a number of
distinct pouches, opening by wide slits into the lower part of the sac.
This sac seems to be nothing but the widened lower end of the ovary, and
the pouches within it to be formed by the folds of the ovary itself. In
each of these pouches a young is wrapped up as in a sheet, and all are
packed in the most economical manner as far as saving space is
concerned, some having their head turned forwards and others backwards.
_This is, therefore, a normal ovarian gestation._ The external genital
opening is situated behind the anus, upon the summit and in the center
of a conical protuberance formed by a powerful sphincter, kept in its
place by two strong transverse muscles attached to the abdominal walls.
The number of young contained in this sac seems to vary. Mr. Jackson
counted nineteen; I have seen only eight or nine in the specimens sent
by Mr. Cary, but since these were open when received it is possible that
some had been taken out. However, their size is most remarkable in
proportion to the mother. In a specimen of _Emb. jacksoni_ 10½ inches
long and 4½ high the young were nearly 3 inches long and 1 inch high;
and in an _Emb. caryi_ 8 inches long and 3¼ high the young were 2¾
inches long and ⅞ of an inch high. Judging from their size, I suspected
for some time that the young could move in and out of this sac like
young opossums, but on carefully examining the position of the young in
the pouches, and also the contracted condition of the sphincter at the
external orifice of the sexual organs, I remained satisfied that this
could not be the case, and that the young which Mr. Jackson found so
lively after putting them in a bucket of salt water had then for the
first time come into free contact with the element in which they were
soon to live; but at the same time it can hardly be doubted that the
water penetrates into the marsupial sac, since these young have fully
developed gills. The size of the young compared with that of the mother
is very remarkable, being full one-third its length in the one, and
nearly so in the other species. Indeed these young Embiotocæ, not yet
hatched, are three or four times larger than the young of a Pomotis (of
the same size) a full year old. In this respect these fishes differ from
all the other viviparous species known to us. There is another feature
about them of considerable interest, that while the two adults differ
markedly in coloration, the young have the same dress, light yellowish
olive with deeper and brighter transverse bands, something like the
young trout and salmon in their parr dress."

[Illustration:

  FIG. 312.—Viviparous Perch (male), _Hysterocarpus traski_ Gibbons.
    Battle Creek, Sacramento River. (Photograph by Cloudsley Rutter.)
]



                              CHAPTER XXII
                      CHROMIDES AND PHARYNGOGNATHI


=SUBORDER Chromides.=—The suborder _Chromides_ contains spiny-rayed
fishes similar to the perch-like forms in most regards, but strikingly
distinguished by the complete union of the lower pharyngeal bones, as in
the _Holconoti_ and _Pharyngognathi_, and still more remarkably by the
presence of but one nasal opening on each side. In all the perch-like
fishes and in nearly all others there are two nasal openings or nostrils
on each side, these two entering into the same nasal sac. In all the
_Chromides_ the lateral line is incomplete or interrupted, and the
scales are usually large and ctenoid.

=The Cichlidæ.=—The suborder _Chromides_ includes two families,
_Cichlidæ_, and _Pomacentridæ_. The _Cichlidæ_ are fresh-water fishes of
the tropics, characterized by the presence of three to ten spines in the
anal fin. In size, color, appearance, habits, and food value they bear a
striking resemblance to the fresh-water sunfishes, or _Centrarchidæ_, of
the eastern United States. This resemblance is one of analogy only, for
in structure the _Cichlidæ_ have no more in common with the
_Centrarchidæ_ than with other families of perch or bass. The numerous
species of _Cichlidæ_ are confined to tropical America and to
corresponding districts in Africa and western Asia. _Tilapia nilotica_
abounds in the Nile. _Tilapia galilæa_ is found in the river Jordan and
the Lake of Galilee. This species is supposed to form part of the great
draught of fishes recorded in the Gospels, and a black spot on the side
is held to commemorate the touch of Simon Peter. Numerous other species
of _Cichlidæ_, large and small, abound in central Africa, even in the
salt ditches of the Sahara.

The species of _Cichla_, especially _Cichla ocellaris_, of the rivers of
South America, elongate and large-mouthed, bear a strong analogy to the
black bass of farther north. A vast number of species belonging to
_Heros_, _Acara_, _Cichlasoma_, _Geophagus_, _Chætobranchus_, and
related genera swarm in the Amazon region. Each of the large rivers of
Mexico has one or more species; one of these, _Heros cyanoguttatus_,
occurs in the Rio Grande and the rivers of southern Texas, its range
corresponding with that of _Tetragonopterus argentatus_, just as the
range of the whole family of _Cichlidæ_ corresponds with that of the
_Characinidæ_. No other species of either family enters the United
States. A similar species, _Heros tetracanthus_, abounds in the rivers
of Cuba, and another, _Heros beani_, called the mojarra verde, in the
streams of Sinaloa. In the lakes and swamps of Central America
_Cichlidæ_ and _Characinidæ_ are very abundant. One fossil genus is
known, called _Priscacara_ by Cope. _Priscacara clivosa_ and other
species occur in the Eocene of Green River and the Great Basin of Utah.
In this genus vomerine teeth are said to be present, and there are three
anal spines. None of the living _Cichlidæ_ have vomerine teeth.

[Illustration:

  FIG. 313.—Garibaldi (scarlet in color), _Hypsypops rubicunda_
    (Girard). La Jolla, San Diego, Cal.
]

[Illustration:

  FIG. 314.—_Pomacentrus leucostictus_ (Müller & Troschel), Damsel-fish.
    Family _Pomacentridæ_.
]

=The Damsel-fishes: Pomacentridæ.=—The _Pomacentridæ_, called
rock-pilots or damsel-fishes, are exclusively marine and have in all
cases but two anal spines. The species are often very brilliantly
colored, lustrous metallic blue and orange or scarlet being the
prevailing shades among the bright-colored species. Their habits in the
reef pools correspond very closely with those of the _Chætodontidæ_.
With the rock-pilots, as with the butterfly-fishes, the exceeding
alertness and quickness of movement make up for lack of protective
colors. With both groups the choice of rocky basins, crevices in the
coral, and holes in coral reefs preserves them from attacks of enemies
large enough to destroy them. In Samoa the interstices in masses of
living coral are often filled with these gorgeous little fishes. The
_Pomacentridæ_ are chiefly confined to the coral reefs, few ranging to
the northward of the Tropic of Cancer. Sometimes the young are colored
differently from the adult, having sky-blue spots and often ocelli on
the fins, which disappear with age. But one species _Chromis chromis_,
is found in the Mediterranean. _Chromis punctipinnis_, the blacksmith,
is found in southern California, and _Chromis notatus_ is the common
dogoro of Japan. One of the largest species, reaching the length of a
foot, is the Garibaldi, _Hypsypops rubicundus_, of the rocky shores of
southern California. This fish, when full grown, is of a pure bright
scarlet. The young are greenish, marked with blue spots. Species of
_Pomacentrus_, locally known as pescado azul, abound in the West Indies
and on the west coast of Mexico. _Pomacentrus fuscus_ is the commonest
West Indian species, and _Pomacentrus rectifrenum_ the most abundant on
the west coast of Mexico, the young, of an exquisite sky-blue, crowding
the rock pools. _Pomacentrus_ of many species, blue, scarlet, black, and
golden, abound in Polynesia, and no rock pool in the East Indies is
without several forms of this type. The type reaches its greatest
development in the south seas. About forty different species of
_Pomacentrus_ and _Glyphisodon_ occur in the corals of the harbor of
Apia in Samoa.

[Illustration:

  FIG. 315.—Cockeye Pilot, _Glyphisodon marginatus_ (Bloch). Cuba.
]

Almost equally abundant are the species of _Glyphisodon_. The "cockeye
pilot," or jaqueta, _Glyphisodon marginatus_, green with black bands,
swarms in the West Indies, occasionally ranging northward, and is
equally common on the west coast of Mexico. _Glyphisodon abdominalis_
replaces it in Hawaii, and the Asiatic _Glyphisodon saxatilis_ is
perhaps the parent of both. _Glyphisodon sordidus_ banded with pale and
with a black ocellus below the soft dorsal is very common from Hawaii to
the Red Sea, and is a food-fish of some importance. _Glyphisodon
cœlestinus_ blue, with black bands, abounds in the south seas.

The many species of _Amphiprion_ are always brilliant, red or orange,
usually marked by one or two cross-bands of creamy blue. _Amphiprion
melanopus_ abounds in the south seas. _Azurina hirundo_ is a slender
species of lower California of a brilliant metallic blue. All these
species are carnivorous, feeding on shrimps, worms, and the like.

[Illustration:

  FIG. 316.—Indigo Damsel fish, _Microspathodon dorsalis_ (Gill).
    Mazatlan, Mex.
]

_Microspathodon_ is herbivorous, the serrated incisors being loosely
implanted in the jaws. _Microspathodon dorsalis_, of the west coast of
Mexico, is of a deep indigo-blue color, with streamer-like fins.
_Microspathodon chrysurus_, of the West Indian coral reefs, black with
round blue spots and the tail yellow. This family is probably of recent
origin, as few fossils are referred to it. _Odonteus pygmæus_ of the
Eocene perhaps belongs to it.

=Suborder Pharyngognathi.=—The wrasses and parrot-fishes, constituting
the group called _Pharyngognathi_ (φαρύγξ, gullet; γνάθος, jaw), by
Johannes Müller, have the lower pharyngeal bones much enlarged and
solidly united, their teeth being either rounded or else flat and paved.
The nostrils, ventral fins, pectoral fins and shoulder-girdle are of the
ordinary perch-like type. The teeth are, however, highly specialized,
usually large and canine-like, developed in the jaws only, and the gills
are reduced in number, 3½ instead of 4, with no slit behind the last
half gill. The scales are always cycloid and are usually large. In the
tropical forms the vertebræ are always twenty-four in number (10 + 14),
but in northern forms the number is largely increased with a
proportionate increase in the number and strength of the dorsal spines.
All the species are strictly marine, and the coloration is often the
most highly specialized and brilliant known among fishes, the
predominant shade being blue.

[Illustration:

  FIG. 317.—Tautog, _Tautoga onitis_ (L.). Wood's Hole, Mass.
]

All are carnivorous, feeding mainly on crustaceans and snails, which
they crush with their strong teeth, there being often a strong canine at
the posterior end of the premaxillary, which holds the snail while the
lower jaw acts upon it. The species are very numerous and form the most
conspicuous feature in the fish markets of every tropical port. They
abound especially in the pools and openings in the coral reefs. All are
good for food, though all are relatively flavorless, the flesh being
rather soft and not oily.

=The Wrasse Fishes: Labridæ.=—The principal family is that of the
_Labridæ_, characterized by the presence of separate teeth in the front
of the jaws. Numerous fossil species are known from the Eocene and
Miocene. Most of these are known only from the lower pharyngeal bones.
_Labrodon_ is the most widely diffused genus, probably allied to
_Labrus_, but with a pile of successional teeth beneath each functional
tooth. The species are mostly from the Miocene.

[Illustration:

  FIG. 318.—Tautog, _Tautoga onitis_ (L.). (From life by Dr. R. W.
    Shufeldt.)
]

The northern forms of _Labridæ_ are known as wrasse on the coasts of
England. Among these are _Labrus bergylta_, the ballan wrasse; _Labrus
viridis_, the green wrasse; _Labrus ossiphagus_, the red wrasse; and
_Labrus merula_, the black wrasse. _Acantholabrus palloni_ and
_Centrolabrus exoletus_ have more than three anal spines. The latter
species, known as rock cook, is abundant in western Norway, as far north
as Throndhjem, its range extending to the northward beyond that of any
other Labroid. Allied to these, on the American coast, is the tautog or
blackfish, _Tautoga onitis_, a common food-fish, dusky in color with
excellent white flesh, especially abundant on the coast of New England.
With this, and still more abundant, is the cunner or chogset,
_Tautogolabrus adspersus_, greenish-blue in color, the flesh being also
more or less blue. This fish is too small to have much value as food,
but it readily takes the hook set for better fishes.

[Illustration:

  FIG. 319.—Capitaine or Hogfish, _Lachnolaimus falcatus_. Florida.
]

In the Mediterranean are found many species of _Crenilabrus_, gaily
colored, each species having its own peculiar pattern and its own
arrangement of inky spots. Among these are _Crenilabrus mediterraneus_,
_Crenilabrus pavo_, and _Crenilabrus griseus_. With these are the small
species called _Ctenolabrus rupestris_, the goldsinny, much like the
American cunner, and the long-nosed _Symphodus scina_.

Of the many West Indian species we may notice the Capitaine or hogfish,
_Lachnolaimus maximus_, a great fish, crimson in color, with its fin
spines ending in long streamers; _Bodianus rufus_, the Spanish ladyfish
or pudiano, half crimson, half golden. _Halichæres radiatus_, the
pudding-wife (a mysterious word derived from "oldwife" and the
Portuguese name, pudiano), a blue fish handsomely mottled and streaked.
Of the smaller species, _Clepticus parræ_, the janissary, with very
small teeth, _Halichœres bivittatus_, the slippery-dick, ranging
northward to Cape Hatteras, and _Doratonotus megalepis_, of an intense
grass-green color, are among the most notable. The razor-fish,
_Xyrichthys psittacus_, red, with the forehead compressed to a sharp
edge, is found in the Mediterranean as well as throughout the West
Indies, where several other species of razor-fish also occur.

[Illustration:

  FIG. 320.—Razor-fish, _Xyrichthys psittacus_ (Linnæus). Tortugas, Fla.
]

[Illustration:

  FIG. 321.—Redfish (male), _Pimelometopon pulcher_ (Ayres). San Diego.
]

[Illustration:

  FIG. 322.—_Lepidaplois perditio_ (Quoy & Gaimard). Wakanoura, Japan.
]

Scarcely less numerous are the species of the Pacific Coast of America.
_Pimelometopon pulcher_, the redfish or fathead of southern California,
reaches a length of two feet or more. It abounds in the broad band of
giant kelp which lines the California coast and is a food-fish of much
importance. The female is dull crimson. In the male the head and tail
are black and on the top of the head is developed with age a great
adipose hump. A similar hump is found on the adult of several other
large labroids. Similar species on the coast of South America, differing
in color and size of scales, are _Pimelometopon darwini_, _Trochocopus
opercularis_, and _Bodianus diplotænia_. The señorita, _Oxyjulis
californica_, is a dainty cream-colored little fish of the California
coast, _Halichœres semicinctus_, the kelpfish, light olive, the male
with a blue shoulder bar, is found in southern California. On the west
coast of Mexico are numerous species of _Thalassoma_, _Halichœres_,
_Pseudojulis_, _Xyrichthys_ and _Iniistius_, all different from the
corresponding species in the West Indies, and equally different from the
much greater variety found in Hawaii and in Samoa. About the Polynesian
and West Indian islands abound a marvelous wealth of forms of every
shade and pattern of bright colors—blue, green, golden, scarlet,
crimson, purple—as if painted on with lavish hand and often in the most
gaudy pattern, although at times laid on with the greatest delicacy. The
most brilliant species belong to _Thalassoma_ and _Julis_, the most
delicately colored to _Stethojulis_ and _Cirrhilabrus_. In _Gomphosus_
the snout is prolonged on a long slender tube. In _Cheilio_ the whole
body is elongate. In _Iniistius_ the first two dorsal spines form a
separate fin, the forehead being sharp as in _Xyrichthys_. Other widely
distributed genera are _Anampses_, _Lepidaplois_, _Semicossyphus_,
_Duymæria_, _Platyglossus_, _Pseudolabrus_, _Hologymnosus_,
_Macropharyngodon_, _Coris_, _Julis_, _Hemipteronotus_,
_Novaculichthys_, _Cheilinus_, _Hemigymnus_, and _Cymolutes_.
_Halichœres_ is as abundant in the East Indies as in the West, one of
its species _Halichœres pæcilopterus_ being common as far north as
Hakodate in Japan. In this species as in a few others the sexes are very
different in color, although in most species no external sexual
differences of any sort appear. In the East Indian genus,
_Pseudocheilinus_, the eye is very greatly modified. The cornea is
thickened, forming two additional lens-like structures.

The small family of _Odacidæ_ differs from the Labridæ in having in each
jaw a sharp cutting edge without distinct teeth anteriorly, the
pharyngeal teeth being pavement-like. The scales are small, very much
smaller than in the _Scaridæ_, the body more elongate, and the structure
of the teeth different. The species are mostly Australian, _Odax
balteatus_ being the most abundant. It is locally known as kelpfish.

In the _Siphonognathidæ_ the teeth are much as in the _Odacidæ_, but the
body is very elongate, the snout produced as in the cornet-fishes
(_Fistularia_), and the upper jaw ends in a long skinny appendage.
_Siphonognathus argyrophanes_, from Australia, reaches a length of
sixteen inches.

=The Parrot-fishes: Scaridæ.=—The parrot-fishes, or _Scaridæ_, are very
similar to the _Labridæ_ in form, color, and scales, but differ in the
more or less complete fusion of the teeth, a character which varies in
the different genera.

Of these the most primitive is _Calotomus_, confined to the East Indies
and Polynesia. In this genus the teeth are united at base, their tips
free and imbricated over the surface of the jaw.

The species are dull in color, reddish or greenish. _Calotomus
japonicus_ is the Budai or Igami of Japan. _Calotomus sandwichensis_ and
_Calotomus irradians_ are found in Hawaii, and _Calotomus xenodon_ on
the off-shore islands of Mexico. In _Calotomus_ the dorsal spines are
slender. In _Scaridea_ (_balia_) of the Hawaiian Islands the first
dorsal is formed of pungent spines as in _Sparisoma_.

[Illustration:

  FIG. 323.—Pharyngeals of Italian Parrot-fish, _Sparisoma cretense_
    (L.). _a_, upper; _b_, lower.
]

[Illustration:

  FIG. 324.—Jaws of a Parrot-fish, _Calotomus xenodon_ Gilbert.
]

[Illustration:

  FIG. 325.—_Cryptotomus beryllinus_ Jordan & Swain. Key West, Florida.
]

_Cryptotomus_ of the Atlantic is also a transitional group having the
general characters of _Sparisoma_, but the anterior teeth more separate.
The several species are all small and characteristic of the West Indian
fauna, one species, _Cryptotomus beryllinus_, ranging northward to Long
Island.

[Illustration:

  FIG. 326.—_Sparisoma hoplomystax_ (Cope). Key West.
]

In the large genus _Sparisoma_ the teeth are more completely joined. In
this group, which is found only in the tropical Atlantic, the lower
pharyngeals are broader than long and hexagonal. The teeth of the jaws
are not completely united, the dorsal spines are pungent, the lateral
line not interrupted, and the gill membranes broadly united to the
isthmus.

[Illustration:

  FIG. 327.—_Sparisoma abildgaardi_ (Bloch), Red Parrot-fish. Loro,
    Colorado. Family _Scaridæ_.
]

Of the numerous species the dull-colored _Sparisoma flavescens_ is most
abundant in the West Indies and ranges farther north than any other.
_Sparisoma cretense_, the _Scarus_ of the ancients, is found in the
Mediterranean, being the only member of the family known in Europe and
the only _Sparisoma_ known from outside the West Indian fauna.

Other West Indian species are the red parrot-fish, _Sparisoma
abildgaardi_, _Sparisoma xystrodon_, _Sparisoma hoplomystax_, the last
two being small species about the Florida Keys, and the handsome
_Sparisoma viride_ from the West Indies.

[Illustration:

  FIG. 328.—Jaws of Blue Parrot-fish, _Scarus cæruleus_ (Bloch).
]

_Scarus_ is the great central genus of parrot-fishes. Its members are
especially abundant in Polynesia and the East Indies, the center of
distribution of the group, although some extend their range to western
Mexico, Japan, the Red Sea, and Australia, and a large number are found
in the West Indies. Most of them are fishes of large size, but a few, as
the West Indian _Scarus croicensis_, reach the length of less than a
foot, and other still smaller species (_Scarus evermanni_, _Scarus
bollmani_) are found only in water of considerable depth (200 fathoms).

[Illustration:

  FIG. 329.—Upper pharyngeals of an Indian Parrot-fish, _Scarus
    strongylocephalus_.
]

[Illustration:

  FIG. 330.—Lower pharyngeals of a Parrot-fish, _Scarus
    strongylocephalus_ (Bleeker).
]

[Illustration:

  FIG. 331.—_Scarus emblematicus_ Jordan & Rutter. Jamaica.
]

[Illustration:

  FIG. 332.—_Scarus cœruleus_ (Bloch). Blue Parrot-fish. Loro, Azul.
    Family _Scaridæ_.
]

The genus _Scarus_ is characterized by not only the almost complete
fusion of its teeth, but by numerous other characters. Its lower
pharyngeals are oblong and spoon-shaped, the teeth appearing as a mosaic
on the concave surface. The gill-membranes are scarcely united to the
narrow isthmus, the lateral line is interrupted, the dorsal spines are
flexible, and there are but few scales on the head. These, as well as
the scales of the body, are always large. The most highly specialized of
its species have the teeth deep blue in color, a character which marks
the genus or subgenus _Pseudoscarus_. Of the species of this type, the
loro, _Pseudoscarus cœlestinus_, and the more abundant guacamaia,
_Pseudoscarus guacamaia_ (fig. 215 vol. I) of the West Indies, are
characteristic forms. The perrico, _Pseudoscarus perrico_ of the west
coast of Mexico, and the great blue parrot-fish, or galo, of Hawaii and
Samoa, _Pseudoscarus jordani_, belong to this type. _Pseudoscarus
jordani_ was formerly tabu to the king in Hawaii, and its brilliant
colors and toothsome flesh (when eaten raw) made it the most highly
valued fish at the royal banquets of old Hawaii. It still sells readily
at a dollar or more per pound. To this type belong also the blue
parrot-fish, _Pseudoscarus ovifrons_, of Japan. In the restricted genus
_Scarus_ proper the teeth are pale. The great blue parrot-fish, of the
West Indies, _Scarus cœruleus_, belongs to this group. This species,
deep blue in color, reaches a large size, and the adult has a large
fleshy hump on the forehead. Lesser parrot-fish with pale teeth and with
showy coloration are the West Indian species _Scarus tæniopterus_,
_Scarus vetula_, _Scarus croicensis_, etc.

[Illustration:

  FIG. 333.—_Scarus vetula_ Bloch & Schneider, Parrot-fish. Family
    _Scaridæ_.
]

[Illustration:

  FIG. 334.—Slippery-dick or Doncella, _Halichœres bivittatus_ (Bloch),
    a fish of the coral reefs. Key West. Family _Labridæ_.
]

Very many species of both _Scarus_ and _Pseudoscarus_, green, blue,
red-brown, or variegated, abound about the coral reefs of Polynesia.
About twenty-five species occur in Samoa. _Pseudoscarus latax_ and _P.
ultramarinus_ being large and showy species, chiefly blue. _Pseudoscarus
prasiognathus_ is deep red with the jaws bright blue.

Fossil species referred to _Scarus_ but belonging rather to _Sparisoma_
are found in the later Tertiary. The genera _Phyllodus_, _Egertonia_,
and _Paraphyllodus_ of the Eocene perhaps form a transition from
_Labridæ_ to _Scaridæ_. In _Paraphyllodus medius_ the three median teeth
of the lower pharyngeals are greatly widened, extending across the
surface of the bone.



                             CHAPTER XXIII
                            THE SQUAMIPINNES


[Illustration:

  FIG. 335.—_Monodactylus argenteus_ (Linnæus). From Apia, Samoa. Family
    _Scorpididæ_.
]

=The Squamipinnes.=—Very closely allied to the _Percomorphi_ is the
great group called _Squamipinnes_ (_squama_, scale; _pinna_, fin) by
Cuvier and _Epelasmia_ by Cope. With a general agreement with the
_Percomorphi_, it is distinguished by the more or less complete
soldering of the post-temporal with the cranium. In the more specialized
forms we find also a soldering of the elements of the upper jaw, and a
progressive reduction in the size of the gill-opening. The ventral fin
retains its thoracic insertion, and, as in the perch mackerel-like
forms, it has one spine and five rays, never any more. The ventral fins
are occasionally lost in the adult, as in the _Stromateidæ_, or they may
lose part of their rays. The name _Squamipinnes_ refers to the scaly
fins, the typical species having the soft rays of dorsal, anal, and
caudal, and sometimes of other fins densely covered with small scales.
In various aberrant forms these scales are absent. The name _Epelasmia_
(ἔπι, above; ἐλάσμος, plate) refers to the thin upper pharyngeals
characteristic of certain forms. The transition from this group to the
_Sclerodermi_ is very clear and very gradual. The _Squamipinnes_,
_Sclerodermi_, _Ostracodermi_, and _Gymnodontes_ form a continuous
degenerating series. On the other hand the less specialized
_Squamipinnes_ approach very closely to forms already considered. The
_Antigoniidæ_ are of uncertain affinities, possibly derived from such
forms as _Histiopteridæ_, while _Platax_ show considerable resemblance
to scaly-finned fishes like the _Kyphosidæ_ and _Stromateidæ_. The
_Scorpididæ_ seem intermediate between _Stromateidæ_ and _Platacidæ_. In
such offshoots from _Scombroidei_ or _Percoidei_ the group doubtless had
its origin.

We may begin the series with some forms which are of doubtful affinity
and more or less intermediate between the _Squamipinnes_ and the more
primitive _Percomorphi_.

=The Scorpididæ.=—This family has the general appearance of _Platax_ and
_Ilarches_, but the teeth are not brush-like, and the post-temporal is
free from the skull as in perch-like fishes. The species inhabit the
Pacific. _Scorpis georgianus_ is a food-fish of Australia, with the body
oblong. _Monodactylus argenteus_, the toto of Samoa, is almost orbicular
in form, while _Psettus sebæ_ is twice as deep as long, the
deepest-bodied of all fishes in proportion to its length.

=The Boarfishes: Antigoniidæ.=—The boarfishes (_Antigoniidæ_) are
characterized by a very deep body covered with rough scales, the
post-temporal, as in the _Chætodontidæ_ and the _Zeidæ_, being adnate to
the skull.

[Illustration:

  FIG. 336.—_Psettus sebæ_ Cuv. & Val. East Indies.
]

These fishes bear some resemblance to _Zeus_, but there is no evidence
of close affinity nor is it clear that they are related to the
_Chætodontidæ_. _Capros aper_, the boarfish, is common in southern
Europe, reaching a length of less than a foot, the protractile mouth
suggesting that of a pig. The diamond-fishes, _Antigonia_, are deeper
than long and strongly compressed, the body being covered with roughish
scales. The color is salmon-red and the species live just below the
depths ordinarily explored by fishermen. _Antigonia capros_ is found at
Madeira and in the West Indies, _Antigonia steindachneri_ about Hawaii
and in Japan, while the smaller _Antigonia rubescens_ is abundant in the
Japanese bays at a depth reached by the dredge. An extinct genus,
_Proantigonia_ from the Miocene is said to connect _Antigonia_ with
_Capros_.

=The Arches: Toxotidæ.=—The archers, _Toxotidæ_, have the body
compressed, the snout produced, and the dorsal fin with but five spines.
The skeleton differs widely from that of _Chætodon_ and the family
should perhaps rather find its place among the percoids. _Toxotes
jaculatrix_ is found in the East Indies. The name alludes to its
supposed habit of catching insects by shooting drops of water at them
through its long mouth.

=The Ephippidæ.=—With the typical _Squamipinnes_, the teeth become very
slender, crowded in brush-like bands. The least specialized family is
that of _Ephippidæ_, characterized by the presence of four anal spines
and a recumbent spine before the dorsal. The principal genus, _Ephippus_
(_Scatophagus_), is represented by _Ephippus argus_, a small, bass-like
fish, spotted with black, found in the Indian seas, and ranging
northward to Formosa. Species referred to _Ephippus_ (_Scatophagus_) are
recorded from the Italian Eocene of Monte Bolca, where a species of
_Toxotes_ has been also found.

=The Spadefishes: Ilarchidæ.=—In the _Ilarchidæ_ the dorsal is divided
into two fins, the spinous part being free from scales. In various
regards the species are intermediate between ordinary perch-like forms
and the chætodonts. In these fishes the body is very deep and, with the
soft fins, closely covered with roughish scales. In _Ilarches_
(_Ephippus_), represented by _Ilarches orbis_ of the Indian seas, these
scales are relatively large. This species is a common food-fish from
India to Formosa.

In the American genus, _Chætodipterus_, the scales are quite small. The
spadefish (_Chætodipterus faber_), sometimes called also moonfish or
angel-fish, is a large, deep-bodied fish, reaching a length of two feet.
It is rather common from Cape Cod to Cuba, and is an excellent pan fish,
with finely flavored white flesh. The young are marked by black
cross-bands which disappear with age, and in the adult the
supraoccipital crest is greatly thickened and the skull otherwise
modified. A very similar species, _Chætodipterus zonatus_, occurs on the
west coast of Mexico. Species allied to _Chætodipterus_ are fossil in
the Italian Eocene. The _Drepanidæ_ of the East Indies are close to the
_Ilarchidæ_. _Drepane punctata_ is a large, deep-bodied fish resembling
the spadefish but with larger scales.

[Illustration:

  FIG. 337.—Spadefish, _Chætodipterus faber_ (L.). Virginia.
]

=The Platacidæ.=—Closely related to the _Ilarchidæ_ is also the East
Indian family of _Platacidæ_, remarkable for the very great depth and
compression of the body, which is much deeper than long, and the highly
elevated dorsal and anal still further emphasize this peculiarity of
form. In this group the few dorsal spines are closely attached to the
soft rays and the general color is dusky. In the young the body is
deeper than in the adult and the ventral fins much more produced. The
best-known species is the tsuzume or batfish (_Platax orbicularis_),
which ranges from India through the warm current to northern Japan.
_Platax teira_, farther south, is very similar. _Platax_ _altissimus_,
with a very high dorsal, is a fossil in the Eocene of Monte Bolca.

[Illustration:

  FIG. 338.—Butterfly-fish, _Chætodon capistratus_ Linnæus. Jamaica.
]

=The Butterfly-fishes: Chætodontidæ.=—The central family of
_Squamipinnes_ is that of the butterfly-fishes or _Chætodontidæ_. In
this group the teeth are distinctly brush-like, the mouth small, the
dorsal fin continuous and closely scaly, and the ventral fins with one
spine and five rays. The species are mostly of small size and brilliant
and varied coloration, yellow and black being the leading colors. They
vary considerably with age, the young having the posterior free edges of
the bones of the head produced, forming a sort of collar. These forms
have received the name of _Tholichthys_, but that supposed genus is
merely the young of _Chætodon_. The species of _Chætodontidæ_ abound in
rock pools and about coral reefs in clear water. They are among the most
characteristic forms of these waters and their excessive quickness of
movement compensates for their conspicuous coloration. In these confined
localities they have, however, few enemies. The broad bodies and spinous
fins make them rather difficult for a large fish to swallow. They feed
on small crustaceans, worms, and the like. The analogy to the butterfly
is a striking one, giving rise to the English name, butterfly-fish, the
Spanish mariposa, and the Japanese chochouwo, all having the same
meaning. Fossil chætodonts are rather few, _Chætodon pseudorhombus_ of
the Pliocene of France, _Holocanthus microcephalus_ and _Pomacanthus
subarcuatus_ of the Eocene, being the only species recorded by Zittel.

[Illustration:

  FIG. 339.—Black Angel-fish, _Pomacanthus arcuatus_ (Linnæus).
    Barnegat, New Jersey.
]

In the principal genus, _Chætodon_, the colors are especially bright.
There is almost always a black bar across the eye, and often black
ocelli adorn the fins. This genus is wanting in Europe. _Chætodon
capistratus_, _striatus_, and numerous other species are found in the
West Indies; _Chætodon humeralis_ and _nigrirostris_ are common on the
coast of Mexico. The center of their distribution is in Polynesia and
the East Indian Archipelago. _Chætodon reticulatus_, _lineolatus_,
_ulietensis_, _ornatissimus_, _ephippion_, _setifer_, and _auriga_ are
among the most showy species. Numerous closely related genera are
described. In some of these the snout is prolonged into a long tube,
bearing the jaws at its end. Of this type are _Chelmo_ in India,
_Forcipiger_ in Polynesia, and _Prognathodes_ in the West Indies.
_Heniochus_ (_macrolepidotus_) has one dorsal spine greatly elongated.
_Microcanthus strigatus_, one of the most widely distributed species, is
known by its small scales. _Megaprotodon_ (_triangularis_) has four anal
spines instead of three as in the others.

[Illustration:

  FIG. 340.—Angel-fish or Isabelita, _Holacanthus ciliaris_ (Linnæus).
    Jamaica. Family _Chætodontidæ_.
]

The species of _Holacanthus_, known as angel-fishes, are larger in size,
and their colors are still more showy, being often scarlet or blue. In
this genus the preopercle is armed with a strong spine, and there are
fourteen or more strong spines in the dorsal. This genus has also its
center of distribution in the East Indies, whence two species
(_septentrionalis_ and _ronin_) with concentric stripes of blue range
northward to Japan. _Holacanthus tibicen_, jet-black with one yellow
cross-band, is found from the Riu Kiu Islands southward. The angel-fish
or isabelita (_Holacanthus ciliaris_), orange-red, sky-blue, and golden,
as though gaudily painted, is the best-known species. The vaqueta de dos
colores or rock beauty (_Holacanthus bicolor_), half jet-black, half
golden, is scarcely less remarkable. Both are excellent food-fishes of
the West Indies. _Holacanthus passer_ is a showy inhabitant of the west
coast of Mexico. _Holacanthus diacanthus_, orange, barred with blue, is
one of the gaudiest inhabitants of the coral reefs of Polynesia.
_Holacanthus flavissimus_, golden with some deep-blue markings, and
_Holacanthus nicobariensis_, blackish with white circles, are found with
other species in the same waters.

The genus _Pomacanthus_ (_Pomacanthodes_) includes American species
only, still larger in size and differing from _Holacanthus_ in having
nine to eleven spines only in the dorsal fin. The young of _Pomacanthus_
are blackish, crossed by many curved yellow cross-bands, which disappear
entirely with age. Three species are known, _Pomacanthus arcuatus_, the
black angel, chirivita or portugais, _Pomacanthus paru_, the Indian-fish
or paru of the West Indies, and _Pomacanthus zonipectus_, "Mojarra de
las Piedras," of the west coast of Mexico. All are good food-fishes, but
lacking the brilliant colors of _Holacanthus_ and the fine pattern usual
in _Chætodon_.

[Illustration:

  FIG. 341.—Rock Beauty, _Holacanthus tricolor_ (L.). Puerto Rico.
]

=The Pygæidæ.=—Between the _Chætodontidæ_ and the _Acanthuridæ_ we would
place the extinct family of _Pygæidæ_, of the Eocene. In _Pygæus gigas_
and other species the dorsal spines are strong and numerous; there are 5
to 8 species in the anal fin, the scales are shagreen-like, and the
teeth seem coarser than in the _Chætodontidæ_. The tail is apparently
unarmed, and the soft dorsal, as in _Chætodon_, is much shorter than the
spinous. To this family the Eocene genera, _Aulorhamphus_ (_bolceusis_),
with produced snout, and _Apostasis_ (_croaticus_), with long spinous
dorsal, probably belong.

[Illustration:

  FIG. 342.—The Moorish Idol, _Zanclus canescens_ (Linnæus). From
    Hawaii. Family _Zanclidæ_. (Painting by Mrs. E. G. Norris.)
]

=The Moorish Idols: Zanclidæ.=—The family of _Zanclidæ_ includes a
single species, the Moorish idol or kihi kihi, _Zanclus canescens_. In
this family the scales are reduced to a fine shagreen, and in the adult
two bony horns grow out over the eye. The dorsal spines are prolonged in
filaments and the color is yellow crossed by bars of black. _Zanclus
canescens_ is a very handsome fish with the general appearance and habit
of a _Chætodon_, but the form is more exaggerated. It is found
throughout Polynesia, from Japan to the off-shore islands of Mexico, and
is generally common, though rarely entering rock pools.

_Zanclus eocænus_ is recorded from the Italian Eocene.

=The Tangs: Acanthuridæ.=—In the next family, _Acanthuridæ_, the
surgeon-fishes or tangs, the scales remain small and shagreen-like, the
body is more elongate, the gill-openings still more restricted, and the
teeth are flattened and incisor-like. The pubic bone is more elongate,
and in all the species some sort of armature is developed on the side of
the tail. The spinous dorsal in all is less developed than the soft
dorsal. The species abound in the warm seas, especially about the tide
pools, and are used as food. They undergo considerable changes with age,
the caudal armature being developed by degrees. Nearly all are dull
brown in color, but in some a vivid ornamentation is added. Fossil forms
are found from the Eocene and later. Most of these are referable to
_Teuthis_ and _Acanthurus_.

[Illustration:

  FIG. 343.—_Teuthis cœruleus_ (Bloch & Schneider), Blue Tang. Mexico.
    Family _Teuthididæ_.
]

The principal genus is _Teuthis_, characterized by the presence on each
side of the tail of a sharp, knife-like, movable spine with the point
turned forwards and dropping into a sheath. This spine gives these
fishes their name of surgeon-fish, doctor-fish, lancet-fish, tang,
barbero, etc., and it forms a very effective weapon against fish or man
who would seize one of these creatures by the tail. The species have the
center of distribution in the East Indies and have not reached Europe.
Three species are found in the West Indies. The blue tang (_Teuthis
cœruleus_) is chiefly bright blue. The common tang, _Teuthis chirurgus_,
is brown with bluish streaks, while a third species, _Teuthis bahianus_,
has a forked caudal fin. Very close to this species is _Teuthis
crestonis_, of the west coast of Mexico, and both are closely related to
_Teuthis matoides_, found from India to Hawaii.

[Illustration:

  FIG. 344.—Brown Tang, _Teuthis bahianus_ (Ranzani). Tortugas, Fla.
]

_Teuthis triostegus_, of Japan and Polynesia and the East Indies, is
covered with cross-bands alternately black and pale. In Hawaii this is
replaced by the very similar _Teuthis sandwichensis_. Many species are
found about Hawaii and the other Polynesian Islands. _Teuthis achilles_
has a large blotch of brilliant scarlet on the tail, and _Teuthis
olivaceus_ a bright-colored mark on the shoulder. _Teuthis lineatus_,
yellow with blue stripes, a showily colored fish of the coral reefs, is
often poisonous, its flesh producing ciguatera.

_Zebrasoma_ differs from _Teuthis_ in having but 4 or 5 dorsal spines
instead of 10 or 11. In this genus the soft dorsal fin is very high.
_Zebrasoma flavescens_, sometimes brown, sometimes bright yellow, is
common in Polynesia; _Zebrasoma veliferum_, cross-barred with black, is
also common.

_Ctenochætus_ (_strigosus_), unlike the others, is herbivorous and has
its teeth loosely implanted in the gums. This species, black with dull
orange streaks, was once tabu to the king of Hawaii, who ate it raw, and
common people who appropriated it were put to death.

In _Xesurus_ the caudal lancelet is replaced by three or four bony
tubercles which have no sharp edge. _Xesurus scalprum_ is common in
Japan, and there are three species or more on the west coast of Mexico,
_Xesurus punctatus_ and _Xesurus laticlavius_ being most abundant.

In _Prionurus_ (_microlepidotus_) of the tropical Pacific the armature
is still more degraded, about six small plates being developed.

In _Acanthurus_ (_Monoceros_, _Naseus_), the unicorn-fish and its
relatives, the ventral fins are reduced, having but three soft rays, the
caudal spines are very large, blunt, immovable, one placed in front of
the other. In most of the species of _Acanthurus_ a long, bony horn
grows forward from the cranium above the eye. This is wanting in the
young and has various degrees of development in the different species,
in some of which it is wholly wanting. The species of _Acanthurus_ reach
a large size, and in some the caudal spines are bright scarlet, in
others blue. _Acanthurus unicornis_, the unicorn-fish, is the commonest
species and the one with the longest horn. It is abundant in Japan, in
Hawaii, and in the East Indies.

_Axinurus thynnoides_ of the East Indies has a long, slim body, with
slender tail like a mackerel.

=Suborder Amphacanthi, the Siganidæ.=—The _Amphacanthi_ (ἄμφϊ,
everywhere; ἄκανθα, spine) are spiny-rayed fishes certainly related to
the _Teuthididæ_, but differing from all other fishes in having the last
ray of the ventrals spinous as well as the first, the formula being I.
4, I. The anal fin has also six or seven spines; and the maxillary is
soldered to the premaxillary. The skeleton is essentially like that of
the _Acanthuridæ_.

The single family, _Siganidæ_, contains fishes of moderate size, valued
as food, and abounding about rocks in shallow water from the Red Sea to
Tahiti. The coloration is rather plain olive or brown, sometimes with
white spots, sometimes with bluish lines. The species are very much
alike and all belong to the single genus _Siganus_. One species,
_Siganus fuscescens_, dusky with small, pale dots, is a common food-fish
of Japan. Others, as _Siganus oramin_ and _Siganus vermiculatus_, occur
in India, and _Siganus punctatus_, known as lo, abounds about the coral
reefs of Samoa. _Siganus vulpinus_ differs from the others in the
elongate snout.

A fossil genus, _Archoteuthis_ (_glaronensis_), is found in the Tertiary
of Glarus. It differs from _Siganus_ in the deeper body and in the
presence of six instead of seven spines in the anal fin.

The real relationship of the _Siganidæ_ is still uncertain, but the
family is probably most nearly allied to the _Acanthuridæ_, with which
the species were first combined by Linnæus, who included both in his
genus _Teuthis_. In the structure of the vertical fins the _Siganidæ_
resemble the extinct genus _Pygæus_.



                              CHAPTER XXIV
                          SERIES PLECTOGNATHI


=THE Plectognaths.=—Derived directly from the _Acanthuridæ_, from which
they differ by progressive steps of degeneration, are the three
suborders of _Sclerodermi_, _Ostracodermi_, and _Gymnodontes_, forming
together the series or suborder of _Plectognathi_. As the members of
this group differ from one another more widely than the highest or most
generalized forms differ from the _Acanthuridæ_, we do not regard it as
a distinct order. The forms included in it differ from the _Acanthuridæ_
much as the swordfishes differ from ordinary mackerel. The
_Plectognathi_ (πλεϡτός, woven together; γνάθος, jaw) agree in the union
of the maxillary and premaxillary, in the union of the post-temporal
with the skull, in the great reduction of the gill-opening, and in the
elongation of the pelvic bones. All these characters in less degree are
shown in the _Squamipinnes_. We have also the reduction and final entire
loss of ventral fins, the reduction and loss of the spinous dorsal, the
compression and final partial or total fusion of the teeth of the upper
jaw, the specialization of the scales, which change from bony scutes
into a solid coat of mail on the one hand, and on the other are reduced
to thorns or prickles and are finally altogether lost. The number of
vertebræ is also progressively reduced until in the extreme forms the
caudal fin seems attached to the head, the body being apparently
wanting. Throughout the group poisonous alkaloids are developed in the
flesh. These may produce the violent disease known as ciguatera,
directly attacking the nervous system. See p. 182, vol. I.

The three suborders of plectognathous are easily recognized by external
characters. In the _Sclerodermi_ (σκλερός, hard; δέρμα, skin) the
spinous dorsal is present and the body is more or less distinctly scaly.
The teeth are separate and incisor-like and the form is compressed. In
the _Ostracodermi_ (ὀστράκος, a box; δέρμα, skin) there is no spinous
dorsal, the teeth are slender, and the body is inclosed in an immovable,
bony box. In the _Gymnodontes_ (γυμνός, naked; ὀδούς, tooth) the teeth
are fused into a beak like that of a turtle, either continuous or
divided by a median suture in each jaw, the spinous dorsal is lost, and
the body is covered with thorns or prickles or else is naked.

=The Scleroderms.=—The _Sclerodermi_ include three recent and one
extinct families. Of the recent forms, _Triacanthidæ_ is the most
primitive, having the ventral fins each represented by a stout spine and
the skin covered with small, rough scales. The dorsal has from four to
six stiff spines.

_Triacanthodes anomalus_ is found in Japan, _Hollardia hollardi_ in
Cuba. _Triacanthus brevirostris_, with the first spine very large, is
the common hornfish of the East Indies ranging northward to Japan.

[Illustration:

  FIG. 345.—The Trigger-fish, _Balistes carolinensis_ Gmelin. New York.
]

=The Trigger-fishes: Balistidæ.=—The _Balistidæ_, or trigger-fishes,
have the body covered with large rough scales regularly arranged. The
first dorsal fin is composed of a short stout rough spine, with a
smaller one behind it and usually a third so placed that by touching it
the first spine may be set or released. This peculiarity gives the name
of trigger-fish as well as the older name of _Balistes_, or cross-bow
shooter. There are no ventral fins, the long pelvis ending in a single
blunt spine. The numerous species of trigger-fishes are large coarse
fishes of the tropical seas occasionally ranging northward. The center
of distribution is in the East Indies, where many of the species are
most fantastically marked. _Balistes carolinensis_, the leather-jacket,
or cucuyo, is found in the Mediterranean as also on the American coast.
_Balistes vetula_, the oldwife, oldwench, or cochino, marked with blue,
is common in the West Indies, as are several other species, as
_Canthidermis sufflamen_, the sobaco, and the jet-black _Melichthys
piceus_, the black oldwife, or galafata. Several species occur on the
Pacific Coast of Mexico, the Pez Puerco, _Balistes verres_, being
commonest. Still others are abundant about the Hawaiian Islands and
Japan. The genus _Balistapus_, having spinous plates on the tail,
contains the largest number of species, these being at the same time the
smallest in size and the most oddly colored. _Balistapus aculeatus_ and
_Balistapus undulatus_ are common through Polynesia to Japan. Most of
the tropical species of _Balistidæ_ are more or less poisonous, causing
ciguatera, the offensive alkaloids becoming weaker in the northern
species. _Melichthys radula_ abounds in Polynesia. In this species great
changes take place at death, the colors changing from blue and mottled
golden green to jet black. Other abundant Polynesian species are
_Xanthichthys lineopunctatus_, _Balistes vidua_, _Balistes bursa_, and
_Balistes flavomarginatus_.

[Illustration:

  FIG. 346.—File-fish, _Osbeckia lævis_ (_scripta_). Wood's Hole, Mass.
]

[Illustration:

  FIG. 347.—The Needle-bearing File-fish, _Amanses scopas_ of Samoa.
]

=The File-fishes: Monacanthidæ.=—Closely related to the _Balistidæ_ are
the _Monacanthidæ_, known as filefishes, or foolfishes. In these the
body is very lean and meager, the scales being reduced to shagreen-like
prickles. The ventral fins are replaced by a single movable or immovable
spine, which is often absent, and the first dorsal fin is reduced to a
single spine with sometimes a rudiment behind it. The species are in
general smaller than the _Balistidæ_ and usually but not always dull in
color. They have no economic value and are rarely used as food, the dry
flesh being bitter and offensive. The species are numerous in tropical
and temperate seas, although none are found in Europe. On our Atlantic
coast, _Stephanolepis hispidus_ and _Ceratacanthus schœpfi_ are common
species. In the West Indies are numerous others, _Osbeckia lævis_ and
_Alutera güntheriana_, largest in size, among the commonest. Both of
these are large fishes without ventral spine. _Monacanthus chinensis_,
with a great, drooping dewlap of skin behind the ventral spine, is found
on the coast of China. Of the numerous Japanese species, the most
abundant and largest is _Pseudomonacanthus modestus_, with deep-blue
fins and the ventral spine immovable. Another is _Stephanolepis
cirrhifer_, known as _Kawamuki_, or skin-peeler. _Alutera monoceros_,
and _Osbeckia scripta_, the unicorn fish, abound in the East Indies,
with numerous others of less size and note. In the male of the
Polynesian _Amanses scopas_ (Fig. 347) the tail is armed with a brush of
extraordinarily long needle-like spines.

In _Stephanolepis spilosomus_ the caudal fin is of a brilliant scarlet
color, contrasting with the usual dull colors of these fishes. In
_Oxymonacanthus longirostris_ the body is blue with orange checker-like
spots and the snout is produced in a long tube. About the islands of
Polynesia, filefishes are relatively few, but some of them are very
curious in form or color.

[Illustration:

  FIG. 348.—Common File fish, _Stephanolepis hispidus_ (Linnæus).
    Virginia.
]

=The Spinacanthidæ.=—In the extinct family _Spinacanthidæ_ the body is
elongate, high in front and tapering behind. The first dorsal has six or
seven spines, and there are rough spines in the pectoral. The teeth are
bluntly conical. _Spinacanthus blennioides_ and _S. imperalis_ are found
in the Eocene of Monte Bolca. These are probably the nearest to the
original ancestor among known scleroderms.

=The Trunkfishes: Ostraciidæ.=—The group _Ostracodermi_ contains the
single family of _Ostraciidæ_, the trunkfishes or cuckolds. In this
group, the body is enveloped in a bony box, made of six-sided scutes
connected by sutures, leaving only the jaws, fins and tail free. The
spinous dorsal fin is wholly wanting. There are no ventral fins, and the
outer fins are short and small. The trunkfishes live in shallow water in
the tropical seas. They are slow of motion, though often brightly
colored.

[Illustration:

  FIG. 349.—Horned Trunkfish, Cowfish, or Cuckold, _Lactophrys
    tricornis_ (Linnæus). Charleston, S. C.
]

[Illustration:

  FIG. 350.—Horned Trunkfish, _Ostracion cornutum_ (Linnæus). East
    Indies. (After Bleeker.)
]

[Illustration:

  FIG. 351.—Spotted Trunkfish, _Lactophrys bicaudalis_ (Linnæus).
    Cozumel Island, Yucatan.
]

[Illustration:

  FIG. 352.—Spotted Trunkfish (face view), _Lactophrys bicaudalis_
    (Linnæus).
]

[Illustration:

  FIG. 353.—Spineless Trunkfish, _Lactophrys triqueter_ (Linnæus).
    Tortugas.
]

Against most of their enemies they are protected by the bony case. The
species range from four inches to a foot in length, so far as known.
They are not poisonous, and are often baked in the shell. Three genera
are recognized: _Lactophrys_ with the _carapace_, three-angled;
_Ostracion_ with four angles; and _Aracana_, resembling _Ostracion_, but
with the carapace not closed behind the anal fin. In each of these
genera there is considerable minor variation due to the presence or
absence of spines on the bony shell. In some species, called cuckolds,
or cowfishes, long horns are developed over the eye. Others have spines
on some other part of the shield and some have no spines at all. No
species are found in Europe, and none on the Pacific coast of America.
The three-angled species, called _Lactophrys_, are native chiefly to the
West Indies, sometimes carried by currents to Guinea, and one is
described from Australia. _Lactophrys tricornis_ of the West Indies has
long horns over the eye; _Lactophrys trigonus_ has spines on the lower
parts only. _Lactophrys triqueter_ is without spines, and the fourth
American species, _Lactophrys bicaudalis_, is marked by large black
spots. The species of _Ostracion_ radiate from the East Indies. One of
them, _Ostracion gibbosum_, has a turret-like spine on the middle of the
back, causing the carapace to appear five-angled; _Ostracion diaphanum_
has short horns over the eye, and _Ostracion cornutum_ very long ones;
_Ostracion_ _immaculatus_, the common species of Japan, is without
spines; _Ostracion sebæ_ of Hawaii and Samoa is deep, rich blue with
spots of golden. _Aracana_ is also of East Indian origin; _Aracana
aculeata_, with numerous species, is common in Japan. A fossil species
of _Ostracion_ (_O. micrurum_) is known from the Eocene of Monte Bolca.

[Illustration:

  FIG. 354.—Hornless Trunkfish, _Lactophrys trigonus_ (Linnæus).
    Tortugas, Fla.
]

=The Gymnodontes.=—The group of _Gymnodontes_, having the teeth united
in a turtle-like beak, carry still further the degeneration of scales
and fins. There is no trace of spinous dorsal, or ventral. The scales
are reduced to thorns or prickles, or are lost altogether. All the
species have the habit of inflating themselves with air when disturbed,
thus floating, belly upward, on the surface of the water. Very few, and
these only northern species, are used as food, the flesh of the tropical
forms being generally poisonous, and that often in a higher degree than
any other fishes whatever.

[Illustration:

  FIG. 355.—Skeleton of the Cowfish, _Lactophrys tricornis_ (Linnæus).
]

=The Triodontidæ.=—The most generalized family is that of the
_Triodontidæ_. These fishes approach the _Balistidæ_ in several regards,
having the body compressed and covered with rough scales. The teeth form
a single plate in the lower jaw, but are divided on the median line
above. The compressed, fan-like, ventral flap is greatly distensible.
_Triodon bursarius_, of the East Indies and northward to Japan, is the
sole species of the family.

[Illustration:

  FIG. 356.—Silvery Puffer, _Lagocephalus lævigatus_ (Linnæus).
    Virginia.
]

=The Globefishes: Tetraodontidæ.=—In the _Tetraodontidæ_ (globefishes,
or puffers), each jaw is divided by a median suture. The dorsal and anal
are short, and the ventrals are reduced in number, usually fifteen to
twenty (7 + 13 to 7 + 9). The walls of the belly are capable of
extraordinary distension, so that when inflated, the fish appears like a
globe with a beak and a short tail attached. The principal genus
_Spheroides_ contains a great variety of forms, forming a closely
intergrading series. In some of these the body is smooth, in others more
or less covered with prickles, usually three-rooted. In some the form is
elongate, the color silvery, and the side of the belly with a
conspicuous fold of skin. In these species, the caudal is lunate and the
other fins falcate, and with numerous rays. But these forms (called
_Lagocephalus_) pass by degrees into the short-bodied forms with small
rounded fins, and no clear line has yet been drawn separating the group
into genera. In these species each nostril has a double opening.
_Lagocephalus lagocephalus_, large and silvery, is found in Europe.
_Lagocephalus lævigatus_ replaces it on the Atlantic Coast of North
America. In Japan are numerous forms of this type, the venomous
_Lagocephalus sceleratus_ being one of the best known. Numerous other
Japanese species, _Spheroides xanthopterus_, _rubripes_, _pardalis_,
_ocellatus_, _vermiculatus_, _chrysops_, etc., mark the transition to
typical _Spheroides_. _Spheroides maculatus_ is common on our Atlantic
coast, the puffer, or swell-toad of the coastwise boys who tease it to
cause it to swell. _Spheroides spengleri_ and _S. testudineus_ abound in
the West Indies. _Spheroides politus_ on the west coast of Mexico.

[Illustration:

  FIG. 357.—Puffer, inflated, _Spheroides spengleri_ (Bloch). Wood's
    Hole, Mass.
]

[Illustration:

  FIG. 358.—Puffer, _Spheroides maculatus_ (Schneider). Noank, Conn.
]

In _Tetraodon_ the nasal tentacle is without distinct opening, its tip
being merely spongy. The species of this genus are even more inflatable
and are often strikingly colored, the young sometimes having the belly
marked by concentric stripes of black which disappear with age.
_Tetraodon hispidus_ abounds in estuaries and shallow bays from Hawaii
to India. In Hawaii, it is regarded as the most poisonous of all fishes
(muki-muki) and it is said that its gall was once used to poison arrows.
_Tetraodon fahaka_ is a related species, the first known of the family.
It is found in the Nile. _Tetraodon lacrymatus_, black with white spots,
is common in Polynesia. _Tetraodon aërostaticus_, with black spots, is
frequently taken in Japan, and _Tetraodon setosus_ is frequent on the
west coast of Mexico. This species is subject to peculiar changes of
color. Normally dark brown, with paler spots, it is sometimes deep blue,
sometimes lemon-yellow and sometimes of mixed shades. Specimens showing
these traits were obtained about Clarion Island of the Revillagigedos.
No _Tetraodon_ occurs in the West Indies. _Colomesus psittacus_, a river
fish of the northern part of South America, resembles _Spheroides_, but
shows considerable difference in the skull.

[Illustration:

  FIG. 359.—_Tetraodon meleagris_ (Lacépède). Riu Kiu Islands.
]

But few fossil _Tetraodontidæ_ have been recognized. These are referred
to _Tetraodon_. The earliest is _Tetraodon pygmæus_ from Monte Bolca.

The _Chonerhinidæ_ of the East Indies are globefishes having the dorsal
and anal fins very long, the vertebræ more numerous (12 + 17),
twenty-nine in number. _Chonerhinus naritus_ inhabits the rivers of
Sumatra and Java.

The little family of _Tropidichthyidæ_ is composed of small globefishes,
with a sharply-keeled back, and the nostrils almost, or quite, wanting.
The teeth are as in the _Tetraodontidæ_. The skeleton differs
considerably from that of _Spheroides_, apparently justifying their
separation as a family. The species are all very small, three to six
inches in length, and prettily colored. In the West Indies
_Tropidichthys rostratus_ is found. _Tropidichthys solandri_ abounds in
the South Seas, dull orange with blue spots. _Tropidichthys rivulatus_
is common in Japan and several ether species are found in Hawaii.

[Illustration:

  FIG. 360.—Bristly Globefish, _Tetraodon setosus_ Rosa Smith. Clarion
    Island, Mex.
]

Other species occur on the west coast of Mexico, in Polynesia, and in
the East Indies.

[Illustration:

  FIG. 361.—Porcupine-fish, _Diodon hystrix_ (Linnæus). Tortugas
    Islands.
]

=The Porcupine-fishes: Diodontidæ.=—In the remaining families of
_Gymnodontes_, there is no suture in either jaw, the teeth forming an
undivided beak. The _Diodontidæ_, or porcupine-fishes, have the body
spherical or squarish, and armed with sharp thorns, the bases of which
are so broad as to form a continuous coat of mail. In some of them, part
of the spines are movable, these being usually two-rooted; in others,
all are immovable and three-rooted. All are reputed poisonous,
especially in the equatorial seas.

In _Diodon_ the spines are very long, the anterior ones, at least,
movable. The common porcupine-fish, _Diodon hystrix_, is found in all
seas, and often in abundance. It is a sluggish fish, olive and spotted
with black. It reaches a length of two feet or more, and by its long
spines it is thoroughly protected from all enemies. A second species,
equally common, is the lesser porcupine-fish, _Diodon holacanthus_. In
this species, the frontal spines are longer than those behind the
pectoral, instead of the reverse, as in _Diodon hystrix_. Many species
of _Diodon_ are recorded from the Eocene, besides numerous species from
later deposits. One of these, as _Heptadiodon heptadiodon_ from the
Eocene of Italy, with the teeth subdivided, possibly represents a
distinct family. _Diodon erinaceus_ is found in the Eocene of Monte
Bolca and _Progymnodon hilgendorfi_ in the Eocene of Egypt.

[Illustration:

  FIG. 362.—Rabbit-fish, _Chilomycterus schœpfi_ (Walbaum). Noank, Conn.
]

In the rabbit-fishes (_Chilomycterus_) the body is box-shaped, covered
with triangular spines, much shorter and broader at base than those of
_Diodon_. Numerous species are known.

_Chilomycterus schœpfi_ is the common rabbit-fish, or swell-toad of our
Atlantic coast, light green, prettily varied with black lines. The
larger, _Chilomycterus affinis_, with the pectoral fin spotted with
black, is widely diffused through the Pacific. It is rather common in
Japan, where it is the torabuku, or tiger puffer. It is found also in
Hawaii, and it is once recorded by Dr. Eigenmann from San Pedro,
California, and once by Snodgrass and Heller, from the Galapagos.

=The Head-fishes: Molidæ.=—The headfishes, or _Molidæ_, also called
sunfishes, have the body abbreviated behind so that the dorsal, anal,
and caudal fins seem to be attached to the posterior outline of the
head. This feature, constituting the so-called gephyrocercal tail is a
trait of specialized degradation.

[Illustration:

  FIG. 363.—Headfish (adult), _Mola mola_ (Linnæus). Virginia.
]

_Mola mola_, the common head-fish or sunfish, is found occasionally in
all tropical and temperate seas. Its form is almost circular, having
been compared by Linnæus to a mill-wheel (mola), and its surface is
covered with a rough, leathery skin. It swims very lazily at the surface
of the water, its high dorsal often rising above the surface. It is
rarely used as food, though not known to be poisonous. The largest
example known to the writer was taken at Redondo Beach, California, by
Mr. Thomas Shooter, of Los Angeles. This specimen was 8 feet 2 inches in
length, and weighed 1200 pounds. Another, almost as large, was taken at
San Diego, in April, 1904. No difference has been noticed among
specimens from California, Cape Cod, Japan, and the Mediterranean. The
young, however, differ considerably from the adult, as might be expected
in a fish of such great size and extraordinary form. (See Figs. 109 and
110, Vol. I.)

Fragments named _Chelonopsis_, and doubtfully referred to _Mola_, are
found in the Pliocene of Belgium. Certain jaws of cretaceous age,
attributed to _Mola_, probably belong, according to Woodward, to a
turtle.

[Illustration:

  FIG. 364.—The King of the Mackerel, _Ranzania makua_ Jenkins, from
    Honolulu. (After Jenkins.)
]

In the genus _Ranzania_, the body is more elongate, twice as long as
deep, but as in _Mola_, the body appears as if bitten off and then
provided with a fringe of tail. The species are rarely taken. _Ranzania
truncata_ is found in the Mediterranean and once at Madeira. _Ranzania
makua_, known as the king of the mackerels about Hawaii, is beautifully
colored brown and silvery. This species has been taken once in Japan.

In Hawaii it is believed that all the Scombroid fishes are subject to
the rule of the makua and that they will disappear if this fish be
killed. By a similar superstition, _Regalecus glesne_ is "king of the
herrings" in Norway and about Cape Flattery, _Trachypterus rex
salmonorum_ is "king of the salmon."



                              CHAPTER XXV
                  PAREIOPLITÆ, OR MAILED-CHEEK FISHES


=THE Mailed-cheek Fishes.=—The vast group of _Pareioplitæ_ (_Loricati_)
or mailed-cheek fishes is characterized by the presence of a "bony stay"
or backward-directed process from the third suborbital. This extends
backward across the cheek toward the preopercle. In the most generalized
forms this bony stay is small and hidden under the skin. In more
specialized forms it grows larger, articulates with the preopercle, and
becomes rough or spinous at its surface. Finally, it joins the other
bones to form a coat of mail which covers the whole head. In degenerate
forms it is again reduced in size, finally becoming insignificant.

The more primitive _Pareioplitæ_ (παρεία, cheek; ὁπλιτής, armed) closely
resemble the _Percomorphi_, having the same fins, the same type of
shoulder-girdle, and the same insertion of the ventral fins. In the more
specialized forms the ventral fins remain thoracic, but almost all other
parts of the anatomy are greatly distorted. In all cases, so far as
known to the writer, the hypercoracoid is perforate as in the
_Percomorphi_. There are numerous points of resemblance between the
_Cirrhitidæ_ and the _Scorpænidæ_, and it is probable that the
_Scorpænidæ_ with all the other _Pareioplitæ_ sprang from some perciform
stock allied to _Cirrhitidæ_ and _Latrididæ_.

Fossil mailed-cheek fishes are extremely few and throw little light on
the origin of the group. Those belong chiefly to the _Cottidæ_.
_Lepidocottus_, recorded from the Miocene and Oligocene, seems to be the
earliest genus.

[Illustration:

  FIG. 365.—Rosefish, _Sebastes marinus_ Linnæus. Cape Cod.
]

[Illustration:

  FIG. 366.—Skull of _Scorpænichthys marmoratus_ Girard, showing the
    suborbital stay (_a_).
]

=The Scorpion-fishes: Scorpænidæ.=—The vast family of _Scorpænidæ_, or
scorpion-fishes, comprises such a variety of forms as almost to defy
diagnosis. The more primitive types are percoid in almost all respects,
save in the presence of the subocular stay. Their scales are ctenoid and
well developed. The dorsal spines are numerous and strong. The ventral
fins are complete and normally attached; the anal has three strong
spines. The cranium shows only a trace of spiny ridges, and the five
spines on the preoperculum are not very different from those seen in
some species of bass. The gill-arches are, however, different, there
being but 3½ gills and no slit behind the last. Otherwise the mouth and
pharanx show no unusual characters. In the extremes of the group,
however, great changes take place, the head becomes greatly distorted
with ridges and grooves, the anal spines are lost, and the dorsal spines
variously modified. The scales may be lost or replaced by warts or
prickles and the ventral fins may be greatly reduced. Still the changes
are very gradual, and it is not easy to divide the group into smaller
families.

The most primitive existing genus is doubtless _Sebastes_. The familiar
rosefish, _Sebastes marinus_, is found on both shores of the north
Atlantic. It is bright red in color and is valued as food. As befits a
northern fish, it has an increased number of vertebræ (31) and the
dorsal spines number 15. From its large haddock-like eye it has been
called the Norway haddock. It is an important food-fish in New England
as well as in northern Europe.

[Illustration:

  FIG. 367.—_Sebastolobus altivelis_ Gilbert. Alaska.
]

In the north Pacific _Sebastes_ gives place to _Sebastolobus_, with
three species (_macrochir_, _altivelis_, and _alascanus_), all
bright-red fishes of soft substance and living in rather deep water.
_Sebastolobus_ is characterized by its two-lobed pectoral fin, the lower
rays being enlarged.

The genus _Sebastodes_, with its rougher-headed ally _Sebastichthys_,
with 13 dorsal spines and the vertebræ 27, ranges farther south than
_Sebastes_ and forms one of the most characteristic features of the
fauna of California and Japan, 50 species occurring about California and
25 being already known from Japan. One species (_Sebastichthys
capensis_) is recorded from the Cape of Good Hope, and two,
_Sebastichthys oculatus_ and _S. darwini_, from the coast of Chile.

Within the limits of _Sebastodes_ and _Sebastichthys_ is a very large
range of form and color, far more than should exist within the range of
a natural genus. On the other hand, all attempts at generic subdivision
have failed because the species form a number of almost perfectly
continuous series. At one extreme are species with large mouths, small
scales, relatively smooth cranium, and long gill-rakers. At the other
extreme are robust species, with the head very rough, the mouth
moderate, the scales larger, and the gill-rakers short and thick. Still
other species have slender cranial spines and spots of bright pink in
certain specialized localities. These approach the genus _Helicolenus_
as other species approach _Scorpæna_.

[Illustration:

  FIG. 368.—Priest-fish, _Sebastodes mystinus_ Jordan & Gilbert.
    Monterey, Cal.
]

The various species are known in California as rockfish, or rock-cod, in
Japan as Soi and Mebaru. In both regions they form a large part of the
bulk of food-fishes, the flesh being rather coarse and of moderate
flavor. All the species so far as known are ovoviviparous, the young
being brought forth in summer in very great number, born at the length
of about ¼ of an inch. The species living close to shore are brown,
black, or green. Those living in deeper waters are bright red, and in
still deeper waters often creamy or gray, with the lining of the mouth
and the peritoneum black. The largest species reach a length of two or
three feet, the smallest eight or ten inches. None are found between
Lower California and Peru and none south of Nagasaki in Japan. Of the
California species the following are of most note: _Sebastodes
paucispinis_, the Bocaccio of the fishermen, from its large mouth, is an
elongate fish, dull red in color, and reaching a very large size. In
deeper waters are _Sebastodes jordani_ and _Sebastodes goodei_, the
former elongate and red, the latter more robust and of a very bright
crimson color. _Sebastodes ovalis_, the viuva, and _Sebastodes
entomelas_ are grayish in hue, and the related _Sebastodes proriger_ is
red. The green rockfish _Sebastodes flavidus_ is common along the shore,
as also the black rockfish, known as pêche prêtre or priestfish,
_Sebastodes mystinus_. Less common is _Sebastodes melanops_. Similar to
this but more orange in color is the large _Sebastodes miniatus_.
Somewhat rougher-headed is the small grass rockfish, _Sebastodes
atrovirens_. On the large red rockfish, _Sebastichthys ruberrimus_, the
spinous ridges are all large and rough serrate. On the equally large
_Sebastichthys levis_ these ridges are smooth. Both these species are
bright red in color. _Sebastichthys rubrovinctus_, called the
Spanish-flag, is covered with broad alternating bands of deep crimson
and creamy pink. It is the most handsomely colored of our marine fishes
and is often taken in southern California. _Sebastichthys elongatus_ is
a red species with very large mouth. Several other species small in size
are red, with three or four spots of bright pink. The commonest of these
is the corsair, _Sebastichthys rosaceus_, plain red and golden. Another
species is the green and red flyfish, _Sebastichthys rhodochloris_.
_Sebastichthys constellatus_ is spotted with pink and _Sebastichthys
chlorostictus_ with green. To this group with pink spots the South
American and African species belong, but none of the Japanese.
_Sebastodes aleutianus_ is a large red species common in Alaska and
_Sebastodes ciliatus_ a green one. About the wharves in California and
northward the brown species called _Sebastichthys auriculatus_ is
abundant. In the remaining species the spinous ridges are progressively
higher, though not so sharp as in some of those already named.
_Sebastichthys maliger_ has very high dorsal spines and a golden blotch
on the back. In _Sebastichthys caurinus_ and especially _Sebastichthys
vexillaris_ the spines are very high, but the coloration is different,
being reddish brown. _Sebastichthys nebulosus_ is blue-black with golden
spots. _Sebastichthys chrysomelas_ is mottled black and yellow.
_Sebastichthys carnatus_ is flesh-color and green. _Sebastichthys
rastrelliger_ is a small, blackish-green species looking like
_Sebastodes atrovirens_, but with short gill-rakers. _Sebastichthys
hopkinsi_ and _Sebastichthys gilberti_ are small species allied to it.
The treefish, _Sebastichthys serriceps_, has very high spines on the
head, and the olive body is crowned by broad black bands. Still more
striking is the black-banded rockfish, _Sebastichthys nigrofasciatus_,
with very rough head and bright red body with broad cross-bands of
black.

[Illustration:

  FIG. 369.—_Sebastichthys serriceps_ Jordan & Gilbert. Monterey, Cal.
]

Of the Japanese species the commonest, _Sebastodes inermis_, the Mebaru,
much resembles _Sebastodes flavidus_. _Sebastodes fuscescens_ looks like
_Sebastodes melanops_, as does also _Sebastodes taczanowskii_.
_Sebastodes matsubaræ_ and _S. flammeus_ and _S. iracundus_, bright-red
off-shore species, run close to _Sebastodes aleutianus_. _Sebastichthys
pachycephalus_ suggests _Sebastichthys chrysomelas_. _Sebastodes
steindachneri_ and _S. itinus_ are brighter-colored allies of
_Sebastodes ovalis_ and _Sebastodes scythropus_ and _Sebastodes joyneri_
represent _Sebastodes proriger_. _Sebastichthys trivittatus_, green,
striped with bright golden, bears some resemblance to _Sebastichthys
maliger_. _Sebastichthys elegans_, _Sebastichthys oblongus_, and
_Sebastichthys mitsukurii_, dwarf species, profusely spotted, have no
analogues among the American forms. _Sebastodes glaucus_ of the Kurile
Islands has 14 dorsal spines and is not closely related to any other.
Fourteen dorsal spines are occasionally present in _Sebastichthys
elegans_. All the other species show constantly 13.

[Illustration:

  FIG. 370.—Banded Rockfish, _Sebastichthys nigrocinctus_ (Ayres).
    Straits of Fuca.
]

The genus _Sebastiscus_ has the general appearance of _Sebastodes_, and
like the latter possesses a large air-bladder. It however agrees with
_Scorpæna_ in the possession of but 12 dorsal spines and 24 vertebræ.
The two known species are common in Japan. _Sebastiscus marmoratus_,
mottled brown, is everywhere abundant along the coast, and the pretty
_Sebastiscus albofasciatus_, pink, violet, and golden, represents it in
equal abundance in deeper water.

The genus _Sebastopsis_ differs from _Sebastodes_ only in having no
teeth on the palatines. The species, all of small size and red or varied
coloration, are confined to the Pacific. _Sebastopsis xyris_ occurs in
lower California and _Sebastopsis guamensis_ and _S. scaber_ in
Polynesia. Species of this genus are often found dried in Chinese insect
boxes.

_Helicolenus_ differs from _Sebastiscus_ only in the total absence of
air-bladder. The species are all bright crimson in color, very handsome,
and live in deep water. _Helicolenus dactylopterus_ is rather common in
the Mediterranean, and is sometimes taken in the Gulf Stream, and also
in Japan, where two or three other species occur.

_Neosebastes_ is much like _Sebastodes_, but the suborbital stay bears
strong spines and the dorsal is very high. _Neosebastes panda_ is found
in Australia, and _N. entaxis_ in Japan. _Setarches_ is distinguished by
the cavernous bones of its head. Species are found in both the Atlantic
and Pacific in deep water. Several other peculiar or transitional genera
are found in different parts of the Pacific.

[Illustration:

  FIG. 371.—Florida Lion fish, _Scorpæna grandicornis_ Cuv. & Val. Key
    West.
]

In _Scorpæna_ the head is more uneven in outline than in _Sebastodes_
and _Sebastichthys_, skinny flaps are often present on head and body,
the air-bladder is wanting, there are 12 dorsal spines and 24 vertebræ,
and on each dorsal spine is a small venom-secreting gland. The species
are very numerous, highly varied in color, and found in all warm seas,
being known as scorpion-fishes or _Rascacios_. Two species, _Scorpæna
scrofa_ and _Scorpæna porcus_, are common in the Mediterranean, being
regarded as good food-fishes, though disliked by the fishermen.

Of the numerous West Indian species, _Scorpæna plumieri_, _Scorpæna
grandicornis_, and _Scorpæna brasiliensis_ are best known. _Scorpæna
guttata_ is common in southern California and is an excellent food-fish.
_Scorpæna mystes_ is found on the west coast of Mexico. _Scorpæna
onaria_ and _S. izensis_ are found in Japan. Fossil remains referred to
_Scorpæna_ are recorded from the Tertiary rocks.

In the islands of the Pacific are numerous dwarf species less than three
inches long, which have been set apart as a separate genus,
_Sebastapistes_. The longest known of these is _Sebastapistes
strongensis_, named from Strong Island, abundant in crevices in the
corals throughout Polynesia, and much disliked by fishermen.

[Illustration:

  _Fig. 372._—Sea-scorpion, _Scorpæna mystes_ Jordan. Mazatlan.
]

The genus _Scorpænopsis_ differs from _Scorpæna_ in the absence of
palatine teeth. It is still more fantastic in form and color.
_Scorpænopsis cirrhosa_, _Scorpænopsis fimbriata_, and other species are
widely distributed through the East Indies and Polynesia.

The lion-fishes (_Pterois_) of the tropical Pacific are remarkable for
their long pectoral fins, elongate dorsal spines, and zebra-like
coloration. The numerous species are fantastic and handsomely colored,
but their poisoned, needle-like spines are dreaded by fishermen. They
lurk in crevices in the coral reefs, some of them reaching a foot in
length.

_Inimicus japonicus_, common in Japan, has a depressed and monstrous
head and a generally bizarre appearance. It is usually black in color
but is largely bright red when found among red algæ. A related species,
_Inimicus aurantiacus_, is blackish when near shore, but lemon-yellow in
deep water. (See frontispiece.) A related species in the East Indies is
_Pelor filamentosum_, called _Nohu_ or _Gofu_ in Polynesia.

[Illustration:

  FIG. 373.—Lion-fish or Sausolele (the dorsal spines envenomed),
    _Pterois volitans_ (Linnæus). Family _Scorpænidæ_. (From a specimen
    from Samoa.)
]

Still more monstrous are the species of _Synanceia_, short, thick-set,
irregularly formed fishes, in which the poisoned spines reach a high
degree of venom. The flesh in all these species is wholesome, and when
the dorsal spines are cut off the fishes sell readily in the markets.
These fishes lie hidden in cavities of the reefs, being scarcely
distinguishable from the rock itself. (See Fig. 168, Vol. I.)

The black _Emmydrichthys vulcanus_ of Tahiti lies in crevices of lava,
and could scarcely be distinguished from an irregular lump of lava-rock.

[Illustration:

  FIG. 374.—Black Nohu, or Poison-fish, _Emmydrichthys vulcanus_ Jordan.
    A species with stinging spines, showing resemblance to lumps of lava
    among which it lives. Family _Scorpænidæ_. From Tahiti.
]

A related form, _Erosa erosa_, the daruma-okose of Japan, is monstrous
in form but often beautifully colored with crimson and gray.

In _Congiopus_ the very strong dorsal spines begin in the head, and the
mouth is very small. Dr. Gill makes this genus the type of a distinct
family, _Congiopodidæ_.

Besides these, very many genera and species of small poison-fishes,
called okose in Japan, abound in the sandy bays from Tokio to Hindostan
and the Red Sea. Some of these are handsomely colored, others are
fantastically formed. _Paracentropogon rubripinnis_ and _Minous adamsi_
are the commonest species in Japan. _Trachicephalus uranoscopus_ abounds
in the bays of hina. _Snyderina yamanokami_ occurs in Southern Japan.

[Illustration:

  FIG. 375.—_Snyderina yamanokami_ Jordan & Starks. Family _Scorpænidæ_.
    Satsuma, Japan.
]

But few fossil _Scorpænidæ_ are recorded. _Scorpænopterus siluridens_, a
mailed fish from the Vienna Miocene, with a warty head, seems to belong
to this group, and _Ampheristus toliapicus_, with a broad, depressed
head, is found in the London Eocene, and various Miocene species have
been referred to _Scorpæna_. _Sebastodes rosæ_ is based on a fragment,
probably Pleistocene, from Port Harford, California.

[Illustration:

  FIG. 376.—_Trachicephalus uranoscopus_. Family _Scorpænidæ_. From
    Swatow, China.
]

The small family of the _Caracanthidæ_ consists of little fishes of the
coral reefs of the Pacific. These are compressed in form, and the skin
is rough with small prickles, the head being feebly armed. The species
are rare and little known, brown in color with pale spots.

[Illustration:

  FIG. 377.—Skilfish, _Anoplopoma fimbria_ (Pallas). California.
]

=The Skilfishes: Anoplopomidæ.=—The small family of skilfishes or
_Anoplopomidæ_ consists of two species found on the coast of California
and northward. These resemble the _Scorpænidæ_, having the usual form of
nostrils, and the suborbital stay well developed. The skull is, however,
free from spines, the scales are small and close-set, and the sleek,
dark-colored body has suggested resemblance to the mackerel or hake.
_Anoplopoma fimbria_, known as skilfish, beshow, or coalfish, is rather
common from Unalaska to Monterey, reaching a length of two feet or more.
In the north it becomes very fat and is much valued as food. About San
Francisco it is dry and tasteless.

=The Greenlings: Hexagrammidæ.=—The curious family of greenlings,
_Hexagrammidæ_, is confined to the two shores of the North Pacific. The
species vary much in form, but agree in the unarmed cranium and in the
presence of but a single nostril on each side, the posterior opening
being reduced to a minute pore. The vertebræ are numerous, the scales
small, and the coloration often brilliant. The species are carnivorous
and usually valued as food. They live in the kelp and about rocks in
California and Japan and along the shores of Siberia and Alaska. The
atka-fish (_Pleurogrammus monopterygius_) is one of the finest of
food-fishes. This species reaches a length of eighteen inches. It is
yellow in color, banded with black, and the flesh is white and tender,
somewhat like that of the Lake whitefish (_Coregonus clupeiformis_), and
is especially fine when salted. This fish is found about the Aleutian
Islands, especially the island of Atka, from which it takes its name. It
is commercially known as Atka mackerel.

[Illustration:

  FIG. 378.—Atka-fish, _Pleurogrammus monopterygius_ (Pallas). Atka
    Island.
]

In this genus there are numerous lateral lines, and the dorsal fin is
continuous. In _Hexagrammos_, the principal genus of the family, the
dorsal is divided into two fins, and there are about five lateral lines
on each side.

_Hexagrammos decagrammus_ is common on the coast of California, where it
is known by the incorrect name of rock-trout. It is a well-known
food-fish, reaching a length of eighteen inches. The sexes are quite
unlike in color, the males anteriorly with blue spots, the females
speckled with red or brown.

[Illustration:

  FIG. 379.—Greenling, _Hexagrammos decagrammus_ (Pallas). Sitka.
]

[Illustration:

  FIG. 380.—Cultus Cod, _Ophiodon elongatus_ (Girard). Sitka, Alaska.
]

_Hexagrammos octogrammus_, the common greenfish of Alaska, and the
greenling _Hexagrammos stelleri_, are also well-known species. Close to
the latter species is the _Abura ainame_, or fat cod, _Hexagrammos
otakii_, common throughout Japan. The red rock-trout, _Hexagrammos
superciliosus_, is beautifully variegated with red, the color being
extremely variable. Other species are found in Japan and Kamchatka.
_Agrammus agrammus_ of Japan differs in the possession of but one
lateral line. _Ophiodon elongatus_, the blue cod, cultus cod, or Buffalo
cod of California, is a large fish of moderate value as food, much
resembling a codfish, but with larger mouth and longer teeth. The flesh
and bones are deeply tinged with bluish green. _Cultus_ is the Chinook
name for worthless. _Zaniolepis latipinnis_ is a singular-looking fish,
very rough, dry, and bony, occasionally taken on the California coast.
_Oxylebius pictus_ is a small, handsome, and very active little fish,
whitish with black bands, common among rocks and algæ on the California
coast. It is, however, rarely brought into the markets, as it shows
great skill in escaping the nets.

No fossil _Hexagrammidæ_ are known.

=The Flatheads or Kochi: Platycephalidæ.=—The family of _Platycephalidæ_
consists of spindle-shaped fishes, with flattened, rough heads and the
body covered with small, rough scales. About fifty species occur in the
East Indian region, where the larger ones are much valued as food. The
most abundant species and usually the largest in size is _Platycephalus
insidiator_, the kochi of the Japanese. The genus _Insidiator_ contains
smaller species with larger scales. In all these the head is very much
depressed, a feature which separates them from all the _Scorpænidæ_.
_Hoplichthys langsdorfi_, the nezupo or rat-tail of Japan, is the type
of a separate family, _Hoplichthyidæ_, characterized by a bony armature
of rough plates. _Bembras japonicas_, another little Japanese fish, with
the ventrals advanced in position and the skin with rough plates, is the
type of the family of _Bembradidæ_.

=The Sculpins: Cottidæ.=—The great family of _Cottidæ_ or sculpins is
one especially characteristic of the northern seas, where a great
variety of species is found. These differ in general from the
_Scorpænidæ_, from which they are perhaps derived, in the greater number
of vertebræ and in the relative feebleness or degeneration of the
spinous dorsal, the ventrals, and the scales. In all these regards great
variation exists. In the most primitive genus, _Jordania_, the body is
well scaled, the spinous dorsal well developed, and the ventral rays I,
5. In _Hemitripterus_ a large number of dorsal spines remains, but the
structure in other regards is highly modified. In the most degraded
types, _Cottunculus_, _Psychrolutes_, _Gilbertidia_, which are also
among the most specialized, there is little trace of spinous dorsal, the
scales are wholly lost, and the ventral fin is incomplete. Most of the
species of _Cottidæ_ live on the bottom in shallow seas. Some are found
in deep water and a few swarm in the rivers. All are arctic or
subarctic, none being found to the south of Italy, Virginia, California,
and Japan. None are valued as food, being coarse and tough. Scarcely any
are found fossil.

Of the multitude of genera of _Cottidæ_ we notice a few of the most
prominent. _Jordania zonope_, a pretty little fish of Puget Sound, is
the most primitive in its characters, being closely allied to the
_Hexagrammidæ_.

[Illustration:

  FIG. 381.—_Jordania zonope_ Starks. Puget Sound.
]

_Scorpænichthys marmoratus_, the great sculpin, or cabezon, of
California reaches a length of 2½ feet. It has the ventral rays I, 5,
although almost in all the other sculpins the rays are reduced to I, 3
or I, 4. The flesh has the livid blue color seen in the cultus cod
_Ophiodon elongatus_.

[Illustration:

  FIG. 382.—_Astrolytes notospilotus_ (Girard). Puget Sound.
]

[Illustration:

  FIG. 383.—Irish Lord, _Hemilepidotus jordani_ Bean. Unalaska.
]

[Illustration:

  FIG. 384.—_Triglops pingeli_ Kröyer. Chebucto, Canada.
]

[Illustration:

  FIG. 335.—Buffalo Sculpin, _Enophrys bison_ (Girard). Puget Sound.
]

To _Icelinus_, _Artedius_, _Hemilepidotus_, _Astrolytes_, and related
genera belong many species with the body partly scaled. These are
characteristic of the North Pacific, in which they drop to a
considerable depth. _Icelus_, _Triglops_, and _Artediellus_ are found
also in the North Atlantic, the Arctic fauna of which is derived almost
entirely from Pacific sources. The genus _Hemilepidotus_ contains coarse
species, with bands of scales. The "Irish lord," _Hemilepidotus
jordani_, a familiar and fantastic inhabitant of Bering Sea, is much
valued by the Aleuts as a food-fish, although the flesh is rather tough
and without much flavor. Almost equally common in Bering Sea is the red
sculpin, _Hemilepidotus hemilepidotus_, and the still rougher
_Ceratocottus diceraus_. The stone-sculpin, or buffalo-sculpin,
_Enophrys bison_, with bony plates on the side and rough horns on the
preopercle, is found about Puget Sound and southward. In all these large
rough species from the North Pacific the preopercle is armed with long
spines which are erected when the fish is disturbed. This makes it
almost impossible for any larger fish to swallow them.

[Illustration:

  FIG. 386.—_Ceratocottus diceraus_ (Cuv. & Val.). Tolstoi Bay, Alaska.
]

[Illustration:

  FIG. 387.—_Elanura forficata_ Gilbert. Bering Sea.
]

[Illustration:

  FIG. 388.—Yellowstone Miller's Thumb, _Cottus punctulatus_ (Gill).
    Yellowstone River.
]

The genera _Cottus_ and _Uranidea_ include the miller's thumbs, also
called in America, blob and muffle-jaws, of the Northern rivers. These
little fishes are found in Europe, Asia, and America wherever trout are
found. They lurk under weeds and stones, moving with the greatest
swiftness when disturbed. They are found in every cold stream of the
region north of Virginia, and they vie with the sticklebacks in their
destruction of the eggs and fry of salmon and trout. _Cottus gobio_ is
the commonest species of Europe. _Cottus ictalops_ is the most abundant
of the several species of the eastern United States, and _Cottus asper_
in streams of the Pacific Coast, though very many other species exist in
each of these regions. The genus _Uranidea_ is found in America. It is
composed of smaller species with fewer teeth and fin-rays, the ventrals
I, 3. _Uranidea gracilis_ is the commonest of these, the miller's thumb
of New England. _Rheopresbe fujiyamæ_ is a large river sculpin in Japan.

[Illustration:

  FIG. 389.—Miller's Thumb, _Uranidea tenuis_ Evermann & Meek. Klamath
    Falls.
]

[Illustration:

  FIG. 390.—_Cottus evermanni_ Gilbert. Lost River, Oregon.
]

_Trachidermus ansatus_ is another river species, the "mountain-witch"
(yamanokami) of Japan, remarkable for a scarlet brand on its cheek,
conspicuous in life.

The chief genus of Atlantic sculpins is _Myoxocephalus_, containing
large marine species, in structure much like the species of _Cottus_.
_Myoxocephalus bubalis_ is the European fatherlasher, or proach; the
European sculpin is _Myoxocephalus scorpius_. The very similar daddy
sculpin of New England is _Myoxocephalus grœnlandicus_. This species
swarms everywhere from Cape Cod northward.

[Illustration:

  FIG. 391.—California Miller's Thumb, _Cottus gulosus_ Girard. McCloud
    River, Cal. (Photograph by Cloudsley Rutter.)
]

According to Fabricius, _Myoxocephalus grœnlandicus_ is "abundant in all
the bays and inlets of Greenland, but prefers a stony coast clothed with
seaweed. It approaches the shore in spring and departs in winter. It is
very voracious, preying on everything that comes in its way and pursuing
incessantly the smaller fish, not sparing the young of its own species,
and devouring crustacea and worms. It is very active and bold, but does
not come to the surface unless it be led thither in pursuit of other
fish. It spawns in December and January and deposits its red-colored roe
on the seaweed. It is easily taken with a bait, and constitutes the
daily food of the Greenlanders, who are very fond of it. They eat the
roe raw."

[Illustration:

  FIG. 392.—Pribilof Sculpin, _Myoxocephalus niger_ (Bean). St. Paul
    Island, Bering Sea.
]

The little sculpin, or grubby, of the New England coast is
_Myoxocephalus æneus_, and the larger eighteen-spined sculpin is
_Myoxocephalus octodecimspinosus_. Still more numerous and varied are
the sculpins of the North Pacific, _Myoxocephalus polyacanthocephalus_
being the best known and most widely diffused. _Oncocottus quadricornis_
is the long-horned sculpin of the Arctic Europe, entering the lakes of
Russia and British America. _Triglopsis thompsoni_ of the depths in our
own Great Lakes seems to be a dwarfed and degenerate descendant of
_Oncocottus_.

[Illustration:

  FIG. 393.—18-spined Sculpin, _Myoxocephalus octodecimspinosus_
    (Mitchill). Beasley Point, N. J.
]

[Illustration:

  FIG. 394.—_Oncocottus quadricornis_ (L.). St. Michael, Alaska.
]

The genus _Zesticelus_ contains small soft-bodied sculpins from the
depths of the North Pacific. _Zesticelus profundorum_ was taken in 664
fathoms off Bogoslof Island and _Zesticelus bathybius_ off Japan. In
this genus the body is very soft and the skeleton feeble, the result of
deep-sea life. Another deep-water genus less degraded is _Cottunculus_,
from which by gradual loss of fins the still more degraded
_Psychrolutes_ (_paradoxus_) and _Gilbertidia_ (_sigolutes_) are perhaps
descended. In sculpins of this type the liparids, or sea-snails, may
have had their origin. Among the remaining genera _Gymnocanthus_
(_tricuspis_, etc.) has no vomerine teeth. _Leptocottus_ (_armatus_) and
_Clinocottus_ (_analis_) abound on the coast of California, and
_Pseudoblennius_ (_percoides_) is found everywhere along the shores of
Japan. _Vellitor centropomus_ of Japan is remarkable among sculpins for
its compressed body and long snout. _Dialarchus snyderi_ of the
California rock-pools is perhaps the smallest species of sculpin,
_Blepsias_ (_cirrhosus_), _Nautichthys_ (_oculofasciatus_), and
_Hemitripterus_ (_americanus_), the sea-raven, among the most fantastic.
In the last-named genus the spinous dorsal is many-rayed, as in
_Scorpænidæ_, a fact which has led to its separation by Dr. Gill as a
distinct family. But the dorsal spines are equally numerous in
_Jordania_, which stands at the opposite extreme of the cottoid series.

[Illustration:

  FIG. 395.—_Blepsias cirrhosus_ Pallas. Straits of Fuca.
]

[Illustration:

  FIG. 396.—Sea raven, _Hemitripterus americanus_ (Gmelin). Halifax,
    Nova Scotia.
]

[Illustration:

  FIG. 397.—_Oligocottus maculosus_ Girard. Sitka.
]

In _Ascelichthys_ (_rhodorus_), a pretty sculpin of the rock-pools of
the Oregon region, the ventral fins are wholly lost. _Ereunias
grallator_, a deep-water sculpin from Japan, without ventrals and with
free rays below its pectorals, should perhaps represent a distinct
family, _Ereuniidæ_.

The degeneration of the spinous dorsal in _Psychrolutes_ and
_Gilbertidia_ of the North Pacific has been already noticed. These
genera seem to lead directly from _Cottunculus_ to _Liparis_.

Fossil _Cottidæ_ are few. _Eocottus veronensis_, from the Eocene of
Monte Bolca, is completely scaled, with the ventral rays I, 5. It is
apparently related to _Jordania_, but is still more primitive.
_Lepidocottus_ (_aries_ and numerous other species, mostly from the
Miocene) is covered with scales, but apparently has less than five soft
rays in the ventrals. Remains of _Oncocottus_, _Icelus_, and _Cottus_
are found in Arctic Pleistocene rocks. The family as a whole is
evidently of recent date.

The _Rhamphocottidæ_ consist of a single little sculpin with a large
bony and singularly formed head, found on the Pacific Coast from Sitka
to Monterey. The species is called _Rhamphocottus richardsoni_.

=The Sea-poachers: Agonidæ.=—The sea-poachers or alligator-fishes,
_Agonidæ_, are sculpins inclosed in a coat of mail made by a series of
overlying plates, much like those of the sea-horses or the catfishes of
the family _Loricariidæ_. So far as structure goes, these singular
fishes are essentially like the _Cottidæ_, but with a different and more
perfect armature. The many species belong chiefly to the North Pacific,
a few in the Atlantic and on the coast of Patagonia. Some are found in
considerable depth of water. All are too small to have value as food and
some have most fantastic forms. Only a few of the most prominent need be
noticed. The largest and most peculiar species is _Percis japonicus_ of
the Kurile Islands. Still more fantastic is the Japanese _Draciscus
sachi_ with sail-like dorsal and anal. _Agonus cataphractus_, the
sea-poacher, is the only European species. _Podothecus acipenserinus_,
the alligator-fish, is the commonest species of the North Pacific.
_Pallasina barbata_ is as slender as a pipefish, with a short beard at
the chin. _Aspidophoroides monopterygius_ of the Atlantic and other
similar species of the Pacific lack the spinous dorsal fin.

[Illustration:

  FIG. 398.—_Ereunias grallator_ Jordan & Snyder. Misaki, Japan.
]

[Illustration:

  FIG. 399.—Sleek Sculpin, _Psychrolutes paradoxus_ (Günther). Puget
    Sound.
]

[Illustration:

  FIG. 400.—_Gilbertidia sigolutes_ (Jordan). Puget Sound.
]

[Illustration:

  FIG. 401.—Richardson's Sculpin, _Rhamphocottus richardsoni_ (Günther).
    Puget Sound.
]

[Illustration:

  FIG. 402.—_Stelgis vulsus_ (Jordan & Gilbert). Point Reyes, Cal.
]

[Illustration:

  FIG. 403.—_Draciscus sachi_ Jordan & Snyder. Family _Agonidæ_. Aomori,
    Japan.
]

[Illustration:

  FIG. 404.—Agonoid-fish, _Pallasina barbata_ (Steindachner). Port
    Mulgrave, Alaska.
]

[Illustration:

  FIG. 405.—_Aspidophoroides monopterygius_ (Bloch). Halifax.
]

No fossil _Agonidæ_ are known.

=The Lump-suckers: Cyclopteridæ.=—The lump-suckers, _Cyclopteridæ_, are
structurally very similar to the _Cottidæ_, but of very different habit,
the body being clumsy and the movements very slow. The ventral fins are
united to form a sucking disk by which these sluggish fishes hold fast
to rocks. The skeleton is feebly ossified, the spinous dorsal fin wholly
or partly lost, the skin smooth or covered with bony warts. The slender
suborbital stay indicates the relation of these fishes with the
_Cottidæ_. The species are chiefly Arctic, the common lumpfish or "cock
and hen paddle," _Cyclopterus lumpus_, abounding on both shores of the
North Atlantic. It reaches a length of twenty inches, spawning in
eel-grass where the male is left to watch the eggs. _Cyclopterichthys
ventricosus_ is a large species with smooth skin from the North Pacific.

[Illustration:

  FIG. 406.—Lumpfish, _Cyclopterus lumpus_ (Linnæus). Eastport, Me.
]

[Illustration:

  FIG. 407.—Liparid, _Crystallias matsushimæ_, (Jordan and Snyder).
    Family _Liparididæ_. Matsushima Bay, Japan.
]

=The Sea-snails: Liparididæ.=—The sea-snails, _Liparididæ_ are closely
related to the lumpfishes, but the body is more elongate, tadpole
shaped, covered with very lax skin, like the "wrinkled skin on scalded
milk." In structure the liparids are still more degenerate than the
lumpfishes. Even the characteristic ventral disk is lost in some species
(_Paraliparis_; _Amitra_) and in numerous others the tail is drawn out
into a point (leptocercal), a character almost always a result of
degradation. The dorsal spines are wanting or imbedded in the loose
skin, and all trace of spines on the head is lost, but the
characteristic suborbital stay is well developed. The numerous species
are all small, three to twelve inches in length. They live in Arctic
waters, often descending to great depths, in which case the body is very
soft. One genus, _Enantioliparis_, is found in the Antarctic. In the
principal genus, _Liparis_, the ventral disk is well developed, and the
spinous dorsal obsolete. _Liparis liparis_ is found on both shores of
the North Atlantic, and is subject to large variations in color.
_Liparis agassizi_ is abundant in Japan and northward, and _Liparis
pulchellus_ in California. In the most primitive genus, _Neoliparis_, a
notch in the fin indicates the separation of the spinous dorsal.
_Neoliparis montagui_ is common in Europe, replaced in New England by
_Neoliparis atlanticus_. _Careproctus_, with numerous elongate species,
inhabits depths of the North Pacific. In _Paraliparis_ (or
_Hilgendorfia_) _ulochir_, the ventral disk is gone and the lowest stage
of degradation of the Loricate or _Scorpæna-Cottus_ type of fishes is
reached. No fossil lump-suckers or liparids are recorded, although
remains of _Cyclopterus lumpus_ are found in nodules of glacial clay in
Canada.

[Illustration:

  FIG. 408.—Snailfish, _Neoliparis mucosus_ (Ayres). San Francisco.
]

=The Baikal Cods: Comephoridæ.=—The family of _Comephoridæ_ includes
_Comephorus baikalensis_, a large fresh-water fish of Lake Baikal in
Siberia, having no near affinities with any other existing fish, but now
known to be a mail-cheek fish related to the _Cottidæ_. The body is
elongate, naked, with soft flesh and feeble skeleton. The mouth is
large, with small teeth, and the skull has a cavernous structure. There
are no ventral fins. The spinous dorsal is short and low, the second
dorsal and anal many-rayed, and the pectoral fins are excessively long,
almost wing-like; the vertebræ number 8 + 35 = 43, and unlike most
fresh-water fishes, the species has no air-bladder. Little is known of
the habits of this singular fish. Another genus is recently described
under the name of _Cottocomephorus_.

=Suborder Craniomi: the Gurnards, Triglidæ.=—A remarkable offshoot from
the _Pareioplitæ_ is the suborder of gurnards, known as _Craniomi_
(κράνιον, skull; ὤμος, shoulder). In these fishes the suborbital stay is
highly developed, much as in the _Agonidæ_, bony externally and covering
the cheeks. The shoulder-girdle is distorted, the post-temporal being
solidly united to the cranium, while the postero-temporal is crowded out
of place by the side of the proscapula. In other regards these fishes
resemble the other mail-cheek forms, their affinities being perhaps
closest with the _Agonidæ_ or certain aberrant _Cottidæ_ as _Ereunias_.

In the true gurnards or _Triglidæ_ the head is rough and bony, the body
covered with rough scales and below the pectoral fin are three free rays
used as feelers by the fish as it creeps along the bottom. These free
rays are used in turning over stones, exploring shells and otherwise
searching for food. The numerous species are found in the warm seas. In
Europe, the genus _Trigla_, without palatine teeth and with the lateral
line armed, is represented by numerous well-known species. _Trigla
cuculus_ is a common form of the Mediterranean. _Chelidonichthys_,
similar to _Trigla_ but larger and less fully armed, is found in Asia as
well as in Europe. Several species occur in the Mediterranean.
_Chelidonichthys kumu_ is a common species in Japan, a large fish with
pectorals of a very brilliant variegated blue, like the wings of certain
butterflies.

[Illustration:

  FIG. 409.—Sea-robin, _Prionotus evolans_ (L.). Wood's Hole, Mass.
]

_Lepidotrigla_, with larger scales, has many species on the coasts of
Europe as well as in China and Japan. _Lepidotrigla alata_, a red fish
with a peculiar bony, forked snout, is common in Japan. The American
species of gurnards, having teeth on the palatine, belong to the genus
_Prionotus_. Northward these fishes, known as sea-robins, live along the
shores in shallow water. In the tropics they descend to deeper water,
assuming a red color. _Prionotus carolinus_ is the commonest species in
New England. _Prionotus strigatus_, the striped sea-robin, and
_Prionotus tribulus_, the rough-headed sea-robin, are common species
along the Carolina coast. None have much value as food, being dry and
bony. Numerous fossil species referred to Trigla are found in the
Miocene. _Podopteryx_, from the Italian Miocene, with small pectorals
and very large ventrals, perhaps belongs also to this family, but its
real affinities are unknown.

[Illustration:

  FIG. 410.—Flying Gurnard, _Cephalacanthus volitans_ (L.). Virginia.
]

[Illustration:

  FIG. 411.—_Peristedion miniatum_ Goode & Bean. Depths of the Gulf
    Stream.
]

=The Peristediidæ.=—The _Peristediidæ_ are deep-water sea-robins, much
depressed, with flat heads, a bony coat of mail, and two free feelers on
the pectoral fin instead of three. The species of _Peristedion_ are
occasionally taken with the dredge. _Peristedion cataphractum_ is rather
common in Europe. The extinct _Peristedion urcianense_ is described from
the Pliocene of Orciano, Tuscany.

=The Flying Gurnards: Cephalacanthidæ.=—The flying gurnards,
_Cephalacanthidæ_, differ in numerous respects and are among the most
fantastic inhabitants of the sea. The head is short and bony, the body
covered with firm scales, and the very long, wing-like pectoral fin is
divided into two parts, the posterior and larger almost as long as the
rest of the body. This fin is beautifully colored with blue and brownish
red. The first spine of the dorsal fin is free from the others and more
or less prolonged. The few species of flying gurnard are much alike,
ranging widely in the tropical seas, and having a slight power of
flight. The flying robin, or batfish, called in Spanish volador or
murcielago, _Cephalacanthus volitans_, is common on both coasts of the
Atlantic, reaching a length of eighteen inches. _Cephalacanthus
peterseni_ is found in Japan and _Cephalacanthus orientalis_ in the East
Indies, Japan, and Hawaii. The immature fishes have the pectoral fins
much shorter than in the adult, and differ in other regards.
_Cephalacanthus pliocenicus_ occurs in the Lower Pliocene of Orciano,
Tuscany.

_Petalopteryx syriacus_, an extinct flying gurnard found in the
Cretaceous of Mount Lebanon, is an ally of _Cephalacanthus_. The body is
covered with four-angled bony plates, and the first (free) spine of the
dorsal is enlarged.



                              CHAPTER XXVI
                 GOBIOIDEI, DISCOCEPHALI, AND TÆNIOSOMI


=SUBORDER Gobioidei, the Gobies: Gobiidæ.=—The great family of
_Gobiidæ_, having no near relations among the spiny-rayed fishes, may be
here treated as forming a distinct suborder.

The chief characteristics of the family are the following: The ventral
fins are thoracic in position, each having one spine and five soft rays,
in some cases reduced to four, but never wanting. The ventral fins are
inserted very close together, the inner rays the longest, and in most
cases the two fins are completely joined, forming a single roundish fin,
which may be used as a sucking-disk in clinging to rocks. The
shoulder-girdle is essentially perch-like in form, the cranium is
usually depressed, the bones being without serrature. There is no
lateral line, the gill-openings are restricted to the sides, and the
spinous dorsal is always small, of feeble spines, and is sometimes
altogether wanting. There is no bony stay to the preopercle. The small
pharyngeals are separate, and the vertebræ usually in normal number, 10
+ 14 = 24.

The species are excessively numerous in the tropics and temperate zones,
being found in lakes, brooks, swamps, and bays, never far out in the
sea, and usually in shallow water. Many of them burrow in the mud
between or below tide-marks. Others live in swift waters like the
darters, which they much resemble. A few reach a length of a foot or
two, but most of the species rarely exceed three inches, and some of
them are mature at half an inch.

The largest species, _Philypnus dormitor_, the guavina de rio, is found
in the rivers of Mexico and the West Indies. It reaches a length of
nearly two feet and is valued as food. Unlike most of the others, in
this species there are teeth on the vomer. Other related forms of the
subfamily of _Eleotrinæ_, having the ventral fins separate, are
_Eleotris pisonis_, a common river-fish everywhere in tropical America;
_Eleotris fusca_, a river-fish abounding from Tahiti and Samoa to
Hindostan; _Dormitator maculatus_, the stout-bodied guavina-mapo of the
West Indian regions, with the form of a small carp. _Guavina guavina_ of
Cuba is another species of this type, and numerous other species having
separate ventrals are found in the East Indies, the West Indies, and in
the islands of Polynesia. Some species, as _Valenciennesia strigata_ of
the East Indies and _Vireosa hanæ_ of Japan, are very gracefully
colored. One genus, _Eviota_, is composed of numerous species, all
minute, less than an inch in length. These abound in the crevices in
coral-heads. _Eviota epiphanes_ is found in Hawaii, the others farther
south. _Hypseleotris guntheri_, of the rivers and springs of Polynesia,
swims freely in the water, like a minnow, never hugging the bottom as
usual among gobies.

[Illustration:

  FIG. 412.—Guavina de Rio, _Philypnus dormitor_ (Bloch & Schneider).
    Puerto Rico.
]

[Illustration:

  FIG. 413.—Dormeur, _Eleotris pisonis_ Gmelin. Tortugas, Fla.
]

[Illustration:

  FIG. 414.—Guavina mapo, _Dormitator maculatus_ (Schneider). Puerto
    Rico.
]

[Illustration:

  FIG. 415.—_Vireosa hanæ_ Jordan & Snyder. Misaki, Japan.
]

[Illustration:

  FIG. 416.—Esmeralda de Mar, _Gobionellus oceanicus_ (Pallas). Puerto
    Rico.
]

Of the typical gobies having the ventrals united we can mention but a
few of the myriad forms, different species being abundant alike in fresh
and salt waters in all warm regions. In Europe _Gobius jozo_, _Gobius
ophiocephalus_, and many others are common species. The typical genus
_Gobius_ is known by its united ventrals, and by the presence of silken
free rays on the upper part of the pectoral fin. _Mapo soporator_ swarms
about coral reefs in both Indies. _Gobionellus oceanicus_, the esmeralda
or emerald-fish, is notable for its slender body and the green spot over
its tongue. _Gobiosoma alepidotum_ and other species are scaleless.
_Barbulifer ceuthœcus_ lives in the cavities of sponges. _Coryphopterus
similis_, a small goby, swarms in almost every brook of Japan. The
species of _Pterogobius_ are beautifully colored, banded with white or
black, or striped with red or blue. _Pterogobius virgo_ and _Pterogobius
daimio_ of Japan are the most attractive species. Species of
_Cryptocentrus_ are also very prettily colored.

[Illustration:

  FIG. 417.—_Pterogobius daimio_ Jordan & Snyder. Misaki, Japan.
]

[Illustration:

  FIG. 418.—Darter Goby, _Aboma etheostoma_ Jordan. Mazatlan, Mex.
]

Of the species burrowing in mud the most interesting is the long-jawed
goby, _Gillichthys mirabilis_. In this species the upper jaw is greatly
prolonged, longer than the head, as in _Opisthognathus_ and _Neoclinus_.
In the "American Naturalist" for August, 1877, Mr. W. N. Lockington says
of the long-jawed goby:

"I call it the long-jawed goby, as its chief peculiarity consists in its
tremendous length of jaw. A garpike has a long jaw, and so has an
alligator, and it is not unlikely that the title will call up in the
minds of some who read this the idea of a terrible mouth, armed with a
bristling row of teeth. This would be a great mistake, for our little
fish has no teeth worth bragging about, and does not open his mouth any
wider than a well-behaved fish should do. The great difference between
his long jaws and those of a garpike is that the latter's project
forward, while those of our goby are prolonged backward immensely.

"The long-jawed goby was discovered by Dr. J. G. Cooper in the Bay of
San Diego, among seaweed growing on small stones at the wharf, and in
such position that it must have been out of the water from three to six
hours daily, though kept moist by the seaweed.

[Illustration:

  FIG. 419.—Long-jawed Goby. _Gillichthys mirabilis_ Cooper. Santa
    Barbara.
]

"On a recent occasion a single _Gillichthys_, much larger than any of
the original types, was presented by a gentleman who said that the fish,
which was new to him, was abundant upon his ranch in Richardson's Bay,
in the northern part of the Bay of San Francisco; that the Chinamen dug
them up and ate them, and that he had had about eleven specimens cooked,
and found them good, tasting, he thought, something like eels. The
twelfth specimen he had preserved in alcohol, in the interest of natural
science. This gentleman had the opportunity of observing something of
the mode of life of these fishes, and informed us that their holes,
excavated in the muddy banks of tidal creeks, increase in size as they
go downward, so that the lower portion is below the water-level, or at
least sufficiently low to be kept wet by the percolation from the
surrounding mud.

"When the various specimens now acquired were placed side by side, the
difference in the relative length of their jaws was very conspicuous,
for while in the smallest it was about one-fifth of the total length, in
the largest it exceeded one-third.

"As the fish had now been found in two places in the bay, I thought I
would try to find it also, and to this end sallied out one morning,
armed with a spade, and commenced prospecting in a marsh at Berkeley,
not far from the State University. For a long time I was unsuccessful,
as I did not know by what outward signs their habitations could be
distinguished, and the extent of mud-bank left bare by the retreating
tide was, as compared with my powers of delving, practically limitless.

"At last, toward evening, while digging in the bend of a small creek, in
a stratum of soft, bluish mud, and at a depth of about a foot below a
small puddle, I found five small fishes, which at first I believed to
belong to an undescribed species, so little did they resemble the
typical _G. mirabilis_, but which proved, upon a closer examination, to
be the young of that species. There was the depressed, broad head, the
funnel-shaped ventral 'disk' formed by the union of the two ventral
fins, and the compressed tail of the long-jawed goby, but where were the
long jaws? The jaws were, of course, in their usual place, but their
prolongations had only just begun to grow along the sides of the head,
and were not noticeable unless looked for. A comparison of the various
specimens proved conclusively that the strange-looking appendage is
developed during the growth of the fish, as will be seen by the
following measurements of four individuals:

"In the smallest specimen the maxillary expansion extends beyond the
orbit for a distance about equal to that which intervenes between the
anterior margin of the orbit and the tip of the snout; in No. 2 it
reaches to the posterior margin of the preoperculum; in No. 3 it ends
level with the gill-opening; while in the largest individual it passes
the origin of the pectoral and ventral fins.

"What can be the use of this long fold of skin and cartilage, which is
not attached to the head except where it joins the mouth, and which,
from its gradual development and ultimate large dimensions, must
certainly serve some useful purpose?

"Do not understand that I mean that every part of a creature is of use
to it in its present mode of life, for, as all naturalists know, there
are in structural anatomy, just as in social life, cases of _survival_;
remains of organs which were at some former time more developed,
parallel in their nature to such survivals in costume as the two buttons
on the back of a man's coat, once useful for the attachment of a
sword-belt. But in this fish we have no case of survival, but one of
unusual development; the family (_Gobiidæ_) to which it belongs presents
no similar case, although its members have somewhat similar habits, and
the conviction grows upon us, as we consider the subject, that the long
jaws serve some useful purpose in the economy of the creature. In view
of the half-terrestrial life led by this fish, I am inclined to suspect
that the expansion of the upper jaw may serve for the retention of a
small quantity of water, which, slowly trickling downward into the mouth
and gills, keeps the latter moist when, from an unusually low tide or a
dry season, the waters of its native creek fail, perhaps for several
hours, to reach the holes in which the fishes dwell. It may be objected
to this view that, were such an appendage necessary or even useful,
other species of _Gobiidæ_, whose habits are similar, would show traces
of a similar adaptation. This, however, by no means follows. Nature has
many ways of working out the same end; and it must be remembered that
every real species, when thoroughly known, differs somewhat in habits
from its congeners, or at least from its family friends. To take an
illustration from the mammalia. The chimpanzee and the spider-monkey are
both quadrumanous and both arboreal, yet the end which is attained in
the former by its more perfect hands is reached in the latter by its
prehensile tail.

"Why may not the extremely long channel formed by the jaw of this rather
abnormal member of the goby family be another mode of provision for the
requirements of respiration?"

Of the Asiatic genera, _Periophthalmus_ and _Boleophthalmus_ are
especially notable. In these mud-skippers the eyes are raised on a short
stalk, the fins are strong, and the animal has the power of skipping
along over the wet sands and mud, even skimming with great speed over
the surface of the water. It chases its insect prey among rocks, leaves,
and weeds, and out of the water is as agile as a lizard. Several species
of these mud-skippers are known on the coasts of Asia and Polynesia,
_Periophthalmus barbarus_ and _Boleophthalmus chinensis_ being the best
known. _Awaous crassilabris_ is the common oopu, or river goby, of the
Hawaiian streams, and _Lentipes stimpsoni_ is the mountain oopu, capable
of clinging to the rocks in the rush of torrents. _Paragobiodon
echinocephalus_ is a short thick-set goby with very large head, found in
crevices of coral reefs of Polynesia.

[Illustration:

  FIG. 420.—Pond-skipper, _Boleophthalmus chinensis_ (Osbeck). Bay of
    Tokyo, Japan. (Eye-stalks sunken in preservation.)
]

[Illustration:

  FIG. 421.—Mud-skippy, _Periophthalmus oarbarus_ (L.). Mouth of
    Vaisigono River, Apia, Samoa.
]

In numerous interesting species the first dorsal fin is wanting or much
reduced. The crystal goby, _Crystallogobius nilssoni_, of Europe is one
of this type, with the body translucent. Equally translucent is the
little Japanese shiro-uwo, or whitefish, _Leucopsarion petersi_.
_Mistichthys luzonius_ of the Philippine Islands, another diaphanous
goby, is said to be the smallest of all vertebrates, being mature at
half an inch in length. This minute fish is so very abundant as to
become an important article of food in Luzon. The rank of
"smallest-known vertebrate" has been claimed in turn for the lancelet
(_Asymmetron lucayanum_), the top minnow, _Heterandria formosa_, and the
dwarf sunfish (_Elassoma zonatum_). _Mistichthys luzonius_ is smaller
than any of these, but the diminutive gobies, called _Eviota_, found in
interstices of coral rocks are equally small, and there are several
brilliant but minute forms in the reefs of Samoa. The snake-like
_Eutæniichthys gilli_ of Japanese rivers is scarcely larger, though over
an inch long. _Typhlogobius californiensis_, "the blindfish of Point
Loma," is a small goby, colorless and blind, found clinging in dark
crevices of rock about Point Loma and Dead Man's Island in southern
California.

[Illustration:

  FIG. 422.—_Eutæniichthys gillii_ Jordan & Snyder. Tokyo, Japan.
]

Its eyes are represented by mere rudiments, their loss being evidently
associated with the peculiar habit of the species, which clings to the
under side of stones in relative darkness, though in very shallow water.
The flesh is also colorless, the animal appearing pink in life.

In the Japanese species _Luciogobus guttatus_, common under stones and
along the coast, the spinous dorsal, weak in numerous other species,
finally vanishes altogether. Other gobies are band-shaped or eel-shaped,
the dorsal spines being continuous with the soft rays. Among these are
the barreto of Cuba, _Gobioides broussoneti_, and in Japan _Tænioides
lacepedei_ and _Trypauchen wakæ_, the latter species remarkable for its
strong canines. Fossil gobies are practically unknown. A few fragments,
otoliths, and partial skeletons in southern Europe have been referred to
_Gobius_, but no other genus is represented.

The family of _Oxudercidæ_ contains one species, _Oxuderces dentatus_, a
small goby-like fish from China. It is an elongate fish, without ventral
fins, and with very short dorsal and anal.

=Suborder Discocephali, the Shark-suckers: Echeneididæ.=—Next to the
gobies, for want of a better place, we may mention the singular group of
_Discocephali_ (δίσκος, disk; κεφαλή, head). In this group the first
dorsal fin is transformed into a peculiar laminated sucking-disk, which
covers the whole top of the head and the nape. In other respects the
structure does not diverge very widely from the percoid type, there
being a remarkable resemblance in external characters to the Scombroid
genus _Rachycentron_. But the skeleton shows no special affinity to
_Rachycentron_ or to any perciform fish. The basis of the cranium is
simple, and in the depression of the head with associated modifications
the _Discocephali_ approach the gobies and blennies rather than the
mackerel-like forms.

[Illustration:

  FIG. 423.—Sucking-fish, or Pegador, _Leptecheneis naucrates_
    (Linnæus). Virginia.
]

The _Discocephali_ comprise the single family of shark-suckers or
remoras, the _Echeneididæ_. All the species of this group are pelagic
fishes, widely diffused in the warm seas. All cling by their cephalic
disks to sharks, barracudas, and other free-swimming fishes, and are
carried about the seas by these. They do not harm the shark except by
slightly impeding its movement. They are carnivorous fishes, feeding on
sardines, young herring, and the like. When a shark, taken on the hook,
is drawn out of the water the sucking-fish leaves it instantly, and is
capable of much speed in swimming on its own account. These fishes are
all dusky in color, the belly as dark as the back, so as to form little
contrast to the color of the shark.

The commonest species, _Leptecheneis naucrates_, called pegapega or
pegador in Cuba, reaches a length of about two feet and is almost
cosmopolitan in its range, being found exclusively on the larger sharks,
notably on _Carcharias lamia_. It has 20 to 22 plates in its disk, and
the sides are marked by a dusky lateral band.

Almost equally widely distributed is the smaller remora, or shark-sucker
(_Echeneis remora_), with a stouter body and about 18 plates in the
cephalic disk. This species is found in Europe, on the coast of New
York, in the West Indies, in California, and in Japan, but is nowhere
abundant. Another widely distributed species is _Remorina albescens_
with 13 plates in its disk. _Remoropsis brachyptera_, with 15 plates and
a long soft dorsal, is also occasionally taken. _Rhombochirus osteochir_
is a rare species of the Atlantic with 18 plates, having the pectoral
rays all enlarged and stiff. The louse-fish (_Phtheirichthys lineatus_)
is a small and slender remora having but 10 plates in its disk. It is
found attached, not to sharks, but to barracudas and spearfishes.

[Illustration:

  FIG. 424.—_Rhombochirus osteochir_ (Cuv. & Val.). Wood's Hole, Mass.
]

A fossil remora is described from the Oligocene shales in Glarus,
Switzerland, under the name of _Opisthomyzon glaronensis_. It is
characterized by the small disk posteriorly inserted. Its vertebræ are
10 + 13 = 24 only. Dr. Storms gives the following account of this
species:

"A careful comparison of the proportion of all the parts of the skeleton
of the fossil _Echeneis_ with those of the living forms, such as
_Echeneis naucrates_ or _Echeneis remora_, shows that the fossil differs
nearly equally from both, and that it was a more normally shaped fish
than either of these forms. The head was narrower and less flattened,
the preoperculum wider, but its two jaws had nearly the same length. The
ribs, as also the neural and hæmal spines, were longer, the tail more
forked, and the soft dorsal fin much longer. In fact it was a more
compressed type, probably a far better swimmer than its living
congeners, as might be expected if the smallness of the adhesive disk is
taken into account."

Concerning the relations of the _Discocephali_ Dr. Gill has the
following pertinent remarks:

"The family of _Scomberoides_ was constituted by Cuvier for certain
forms of known organization, among which were fishes evidently related
to _Caranx_, but which had free dorsal spines. Dr. Günther conceived the
idea of disintegrating this family because, _inter alias_, the typical
_Scomberoides_ (family _Scombridæ_) have more than 24 vertebræ and
others (family _Carangidæ_) had just 24. The assumption of Cuvier as to
the relationship of _Elacate_ (_Rachycentron_) was repeated, but
inasmuch as it had 'more than 24 vertebræ' (it had 25 = 12 + 13) it was
severed from the free-spined _Carangidæ_ and associated with the
_Scombridæ_. _Elacate_ has an elongated body, flattened head, and a
longitudinal lateral band; therefore _Echeneis_ was considered to be
next allied to _Elacate_ and to belong to the same family. The very
numerous differences in structure between the two were entirely ignored,
and the reference of the _Echeneis_ to the _Scombridæ_ is simply due to
assumption piled on assumption. The collocation need not, therefore,
longer detain us. The possession by _Echeneis_ of the anterior oval
cephalic disk in place of a spinous dorsal fin would alone necessitate
the isolation of the genus as a peculiar family. But that difference is
associated with almost innumerable other peculiarities of the skeleton
and other parts, and in a logical system it must be removed far from the
_Scombridæ_, and probably be endowed with subordinal distinction. In all
essential respects it departs greatly from the type of structure
manifested in the _Scombridæ_ and rather approximates—but very
distantly—the _Gobioidea_ and _Blennioidea_. In those types we have in
some a tendency to flattening of the head, of anterior development of
the dorsal fin, a simple basis cranii, etc. Nevertheless there is no
close affinity, nor even tendency to the extreme modification of the
spinous dorsal exhibited by _Echeneis_. In view of all these facts
_Echeneis_, with its subdivisions, may be regarded as constituting not
only a family but a suborder.... Who can consistently object to the
proposition to segregate the _Echeneididæ_ as a suborder of
teleocephalous fishes? Not those who consider that the development of
three or four inarticulate rays (or even less) in the front of the
dorsal fin is sufficient to ordinarily differentiate a given form from
another with only one or two such. Certainly the difference between the
constituents of a disk and any rays or spines is much greater than the
mere development or atrophy of articulations. Not those who consider
that the manner of depression of spines, whether directly over the
following, or to the right or left alternately, are of cardinal
importance; for such differences, again, are manifestly of less
morphological significance than the factors of a suctorial disk.
Nevertheless there are doubtless many who will passively resist the
proposition because of a conservative spirit, and who will vaguely refer
to the development of the disk as being a 'teleological modification,'
and as if it were not an actual fact and a development correlated with
radical modifications of all parts of the skeleton at least. But
whatever may be the closest relations of _Echeneis_, or the systematic
value of its peculiarities, it is certain that it is not allied to
_Elacate_ any more than to hosts of scombroid, percoid, and kindred
fishes, and that it differs _in toto_ from it notwithstanding the claims
that have been made otherwise. It is true that there is a striking
resemblance, especially between the young—almost as great, for example,
as that between the placental mouse and the marsupial _Antechinomys_—but
the likeness is entirely superficial, and the scientific ichthyologist
should be no more misled than would be the scientific therologist by the
likeness of the marsupial and placental mammals."

=Suborder Tæniosomi, the Ribbon-fishes.=—The suborder _Tæniosomi_
(ταινία, ribbon; σῶμα, body), or ribbon-fishes, is made up of strange
inhabitants of the open seas, perhaps aberrant derivatives of the
mackerel stock. The body is greatly elongate, much compressed, extremely
fragile, covered with shining silvery skin. The ribbon-fishes live in
the open sea, probably at no very great depth, but are almost never
taken by collectors except when thrown on shore in storms or when
attacked by other fishes and dragged above or below their depth. When
found they are usually reported as sea-serpents, and although perfectly
harmless, they are usually at once destroyed by their ignorant captors.
The whole body is exceedingly fragile; the bones are porous, thin, and
light, containing scarcely any calcareous matter. In the _Tæniosomi_ the
ventral fins are thoracic, formed of one or a few soft rays. More
remarkable is the character of the caudal fin, which is always distorted
and usually not in line with the rest of the body. The teeth are small.
The general structure is not very different from that of the
cutlass-fishes, _Trichiuridæ_, and other degraded offshoots from the
scombroid group. The species are few and, from the nature of things,
very imperfectly known. Scarcely any specimens are perfectly preserved.
When dried the body almost disappears, both flesh and bones being
composed chiefly of water.

=The Oarfishes: Regalecidæ.=—The _Regalecidæ_, or oarfishes, have the
caudal fin obsolete and the ventrals reduced to long filaments,
thickened at the tip. The species reach a length of twenty or thirty
feet, and from their great size, slender forms, and sinuous motion have
been almost everywhere regarded as sea-serpents. The very long anterior
spines of the dorsal fin are tipped with red, and the fish is often and
not untruthfully described as a sea-serpent "having a horse's head with
a flaming red mane."

The great oarfish, _Regalecus glesne_ (see Fig. 237, Vol. I) was long
known to the common people of Norway as king of the herrings, it being
thought that to harm it would be to drive the herring to some other
coast. The name "king of the herrings" went into science as _Regalecus_,
from _rex_, king, and _halec_, herring. The Japanese fancy, which runs
in a different line, calls the creature "Dugunonuatatori," which means
the "cock of the palace under the sea."

The Atlantic oarfish is named _Regalecus glesne_, from the Norwegian
farm of Glesnæs, where the first recorded specimen, described by
Ascanius, was taken 130 years ago. Since then the species has been many
times found on the shores of Great Britain and Norway, and once at
Bermuda.

In this species the body is half-transparent, almost jelly-like, light
blue in color, with some darker cross-stripes, and the head has a long
jaw and a high forehead, suggesting the head of a horse. The dorsal fin
begins on the head, and the first few spines are very long, each having
a red tuft on the end. When the animal is alive these spines stand up
like a red mane.

The creature is harmless, weak in muscle as well as feeble in mind. It
lives in the deep seas, all over the world. After great storms it
sometimes comes ashore. Perhaps this is because for some reason it has
risen above its depth and so lost control of itself. When a deep-water
fish rises to the surface the change of pressure greatly affects it.
Reduction of pressure bursts its blood-vessels, its swim-bladder swells,
if it has one, and turns its stomach inside out. If a deep-water fish
gets above its depth it is lost, just as surely as a surface fish is
when it gets sunk to the depth of half a mile.

Sometimes, again, these deep-sea fishes rush to the shore to escape from
parasites, crustaceans that torture their soft flesh, or sharks that
would tear it.

Numerous specimens have been found in the Pacific, and to these several
names have been given, but the species are not at all clearly made out.
The oldest name is that of _Regalecus russelli_, for the naturalist
Patrick Russell, who took a specimen at Vizagapatam in 1788. I have seen
two large examples of _Regalecus_ in the museum at Tokio, and several
young ones have recently been stranded on the Island of Santa Catalina
in southern California. A specimen twenty-two feet long lately came
ashore at Newport in Orange County, California. The story of its capture
is thus told by Mr. Horatio J. Forgy, of Santa Ana, California:

"On the 22d of February, 1901, a Mexican Indian reported at Newport
Beach that about one mile up the coast he had landed a sea-serpent, and
as proof showed four tentacles and a strip of flesh about six feet long.
A crowd went up to see it, and they said it was about twenty feet long
and like a fish in some respects and like a snake in others. Mr.
Remsberg and I, on the following day, went up to see it, and in a short
time we gathered a crowd and with the assistance of Mr. Peabody prepared
the fish and took the picture you have received.

"It measured twenty-one feet and some inches in length, and weighed
about 500 or 600 pounds.

"The Indian, when he reported his discovery, said it was alive and in
the shallow water, and that he had landed it himself.

"This I very much doubt, but when it was first landed it was in a fine
state of preservation and could have easily been shipped to you, but he
had cut it to such an extent that shipment or preservation seemed out of
the question when we first saw it.

"At the time it came ashore an unusual number of peculiar fishes and
sharks were found. Among others, I found a small oarfish about three
feet long in a bad state of preservation in a piece of kelp. One side of
it was nearly torn off and the other side was decayed."

Mr. C. F. Holder gives this account of the capture of oarfishes in
southern California:

"From a zoological point of view the island of Santa Catalina, which
lies eighteen miles off the coast of Los Angeles County, southern
California, is very interesting, many rare animals being found there.
Every winter the dwellers of the island find numbers of argonaut-shells,
and several living specimens have been secured, one for a time living in
the aquarium which is maintained here for the benefit of students and
the entertainment of visitors. A number of rare and interesting fishes
wander inshore from time to time. Several years ago I found various
Scopeloid fishes, which up to that time had been considered rare, and
during the past few years I have seen one oarfish (_Regalecus russelli_)
alive, while another was brought to me dead. From reports I judge that a
number of these very rare fishes have been observed here. The first was
of small size, not over two feet in length, and was discovered swimming
in shallow water along the beach of Avalon Bay. I had an opportunity to
observe the radiant creature before it died. Its 'topknot'—it can be
compared to nothing else—was a vivid red or scarlet mass of seeming
plumes—the dorsal fins, which merged into a long dorsal fin, extending
to the tail. The color of the body was a brilliant silver sheen splashed
with equally vivid black zebra-like stripes, which gave the fish a most
striking appearance.

"The fish was a fragile and delicate creature, a very ghost of a fish,
which swam along where the water gently lapped the sands with an
undulatory motion, looking like one of its names—the ribbon-fish. The
fortunate finder of this specimen could not be persuaded to give it up
or sell it, and it was its fate to be pasted upon a piece of board,
dried in the sun as a 'curio,' where, as if in retaliation at the
desecration of so rare a specimen, it soon disappeared.

"This apparently was the first oarfish ever seen in the United States,
so at least Dr. G. Brown Goode wrote me at the time that it had not been
reported. In 1899 another oarfish was brought to me, evidently having
been washed in after a storm and found within a few yards of the former
at Avalon. The discoverer of this specimen also refused to allow it to
be properly preserved, or to donate or sell it to any one who would have
sent it to some museum, but, believing it valuable as a 'curio,' also
impaled it, the delicate creature evaporating under the strong heat of
the semitropic sun.

"This, as stated, was the second fish discovered, and during the past
winter (1900) a fine large specimen came in at Newport Beach, being
reported by H. J. Forgy, of Santa Ana. The newspapers announced that a
Mexican had found a young sea-serpent at Newport, and investigation
showed that, as in hundreds of similar instances, the man had found a
valuable prize without being aware of it. According to the account, the
discoverer first saw the fish alive in the surf and hauled it ashore.
Being ignorant of its value, he cut it up, bringing in a part of the
scarlet fins and a slice of the flesh. This he showed to some men, and
led the way to where lay the mutilated remains of one of the finest
oar-or ribbon-fishes ever seen. The specimen was twenty-one feet in
length, and its weight estimated at five hundred pounds. The finder had
so mutilated it that the fish was ruined for almost any purpose. If he
had packed it in salt, the specimen would have returned him the
equivalent of several months' labor. Apparently the man had cut it up in
wanton amusement.

"This recalls a similar incident. I was on one occasion excavating at
San Clemente Island, and had remarked that it was a singular fact that
all the fine stone ollas were broken. 'Nothing strange about that,' said
a half-breed, one of the party. 'I used to herd sheep here, and we
smashed mortars and ollas to pass away time.'"

[Illustration:

  FIG. 425.—Oarfish, _Regalecus russelli_, on the beach at Newport,
    Orange Co., Cal. (Photograph by C. P. Remsberg.)
]

=The Dealfishes: Trachypteridæ.=—The family of _Trachypteridæ_ comprises
the dealfishes, creatures of fantastic form and silvery coloration,
smaller than the oarfishes and more common, but of similar habit.

Just as in Norway the fantastic oarfish was believed to be the king of
the herrings and cherished as such, so among the Indians of Puget Sound
another freak fish is held sacred as the king of the salmon. The people
about Cape Flattery believe that if one does any harm to this fish the
salmon will at once leave the shores. This fable led the naturalists who
first discovered this fish to give it its name of _Trachypterus
rex-salmonorum_.

In Europe a similar species (_Trachypterus atlanticus_) has long been
known by the name of dealfish, or vogmar, neither of these names having
any evident propriety.

The dealfish is one of the most singular of all the strange creatures of
the sea. It reaches a length of three or four feet. Its body is thin as
a knife and would be transparent were it not covered over with a shining
white pigment which gives to the animal the luster of burnished silver.
On this white surface is a large black blotch or two, but no other
colors. The head is something like that of the oarfish, to which animal
the dealfish bears a close relationship. Both have small teeth and
neither could bite if it would, and neither wants to, for they are
creatures of the most inoffensive sort. On the head of the dealfish,
where the oarfish has its mane, is a long, streamer-like fin. At the end
of the tail, instead of the ordinary caudal fin, is a long, slim fin
which projects directly upwards at right angles to the direction of the
back-bone. No other fish shows this strange peculiarity.

The dealfish swims in the open sea close to the surface of the water. It
does not often come near shore, but it is occasionally blown on the
beach by storms. _Trachypterus rex-salmonorum_ has been recorded two or
three times from Puget Sound and twice from California. The finest
specimen known, the one from which our figure is taken, was secured off
the Farallones in 1895 by a fisherman named W. C. Knox, and by him sent
to Stanford University. The specimen is perfect in all its parts, a
condition rare with these fragile creatures, and its picture gives a
good idea of the mysterious king of the salmon.

[Illustration:

  FIG. 426.—Dealfish, or King of the Salmon, _Trachypterus
    rex-salmonorum_ Jordan & Gilbert. Family _Trachypteridæ_. (From a
    specimen taken off the Farallones.)
]

Four of these fishes have been obtained on the coast of Japan, and have
been described and figured by the present writer in the annals of the
Imperial University of Tokyo. These are different from the California
species and are named _Trachypterus ishikawæ_, but they show the same
bright silver color and the same streamers on the head and tail.
Probably they, too, in Japan are kings of something or other, or perhaps
silver swans from the submarine palace, for along such lines the
Japanese fancy is more likely to run.

The young of the dealfish has the caudal symmetrical, and the dorsal
spines and ventral rays produced in very long streamers.

According to Goode and Bean, the dealfishes are "true deep-sea fishes,
which live at very great depths, and are only found when floating dead
on the surface or washed ashore by the waves. Almost nothing is known of
their habits except through Nilsson's observations in the far north.
This naturalist, as well as Olafson, appears to have had the opportunity
of observing them in life. They say that they approach the shore at
flood-tide on sandy, shelving bottoms, and are often left by the
retreating waves. Nilsson's opinion is that its habits resemble those of
the flatfishes, and that they move with one side turned obliquely
upward, the other toward the ground; and he says that they have been
seen on the bottom in two or three fathoms of water, where the fishermen
hook them up with the implements employed to raise dead seals, and that
they are slow swimmers. This is not necessarily the case, however, for
the removal of pressure and the rough treatment by which they were
probably washed ashore would be demoralizing, to say the least.
_Trichiurus_, a fish similar in form, is a very strong, swift swimmer,
and so is _Regalecus_. Whether or not the habits of _Trachypterus
arcticus_, on which these observations were made, are a safe guide in
regard to the other forms is a matter of some doubt, but it is certain
that they live far from the surface, except near the Arctic Circle, and
that they only come ashore accidentally. They have never been taken by
the deep-sea dredge or trawl-net, and indeed perfect specimens are very
rare, the bodies being very soft and brittle, the bones and fin-rays
exceedingly fragile. A considerable number of species have been
described, but in most instances each was based on one or two specimens.
It is probable that future studies may be as fruitful as that of Emery,
who, by means of a series of twenty-three specimens, succeeded in
uniting at least three of the Mediterranean species which for half a
century or more had been regarded as distinct. The common species of the
eastern Atlantic, _Trachypterus atlanticus_, is not rare, one or more
specimens, according to Günther, being secured along the coast of
northern Europe after almost every severe gale. We desire to quote the
recommendation of Dr. Günther, and to strongly urge upon any one who may
be so fortunate as to secure one of these fishes that no attempt should
be made to keep it entire, but that it should be cut into short lengths
and preserved in the strongest spirits, each piece wrapped separately in
muslin."

The family of _Stylephoridæ_ is known from a single specimen of the
species, _Stylephorus chordatus_, taken off Cuba in 1790. In this form
the tail ends in a long, whip-like appendage, twice as long as the head.

No fossil dealfishes or oarfishes are known.



                             CHAPTER XXVII
                         SUBORDER HETEROSOMATA


=THE Flatfishes.=—Perhaps the most remarkable offshoot from the order of
spiny-rayed fishes is the great group of flounders and soles, called by
Bonaparte _Heterosomata_ (ἔτερός, differing; σῶμα, body). The essential
character of this group is found in the twisting of the anterior part of
the cranium, an arrangement which brings both eyes on the same side of
the head. This is accompanied by a great compression of the body, as a
result of which the flounders swim horizontally or lie flat on the sand.
On the side which is uppermost both eyes are placed, this side being
colored, brown or gray or mottled. The lower side is usually plain
white. In certain genera the right side is uppermost, in others the
left. In a very few, confined to the coast of California, the eyes are
on the right or left side indifferently.

The process of the twisting of the head has been already described (see
p. 174, Vol. I). The very young have the body translucent and
symmetrical, standing upright in the water. Soon the tendency to rest on
the bottom sets in, the body leans to left or right, and the lower eye
gradually traverses the front of the head to the other side. This
movement is best seen in the species of _Platophrys_, in which the final
arrangement of the eyes is a highly specialized one.

In some or all of the soles it is perhaps true that the eye turns over
and pierces the cranium instead of passing across it. This opinion needs
verification, and the process should be studied in detail in as many
species as possible. The present writer has seen it in species of
_Platophrys_ only, the same genus in which it was carefully studied by
Dr. Carlo F. Emery of Bologna. In the halibut, and in the more primitive
flounders generally, the process takes place at an earlier stage than in
_Platophrys_.

=Optic Nerves of Flounders.=—In the Bulletin of the Museum of
Comparative Zoology (Vol. XL, No. 5) Professor George H. Parker
discusses the relations of the optic nerves in the group of flounders or
flatfishes.

In the bony fishes the optic nerves pass to the optic lobes of the
brain, the one passing to the lobes of the opposite side simply lying
over the other, without intermingling of fibers, such as takes place in
the higher vertebrates and in the more primitive fishes.

According to Parker's observations, in ordinary bony fishes the right
nerve may be indifferently above or below the other. In 1000 specimens
of ten common species, 486 have the left nerve uppermost and 514 the
right nerve. In most individual species the numbers are practically
equal. Thus, in the haddock, 48 have the left nerve uppermost and 52 the
right nerve.

In the unsymmetrical teleosts or flounders, and soles, this condition no
longer obtains. In those species of flounder with the eyes on the right
side 236 individuals, representing sixteen species, had the left nerve
uppermost in all cases.

Of flounders with the eyes on the left side, 131 individuals,
representing nine species, all have the right nerve uppermost.

[Illustration:

  FIG. 427.—Young Flounder, just hatched, with symmetrical eyes. (After
    S. R. Williams.)
]

There are a few species of flounders in which reversed examples are so
common that the species may be described as having the eyes on the right
or left side indifferently. In all these species, however, whether
dextral or sinistral, the relation of the nerves conforms to the type
and is not influenced by the individual deviation. Thus the starry
flounder (_Platichthys_) belongs to the dextral group. In 50 normal
specimens, the eyes on the right have the left nerve dorsal, while the
left nerve is also uppermost in 50 reversed examples with eyes on the
left. In 15 examples of the California bastard halibut (_Paralichthys
californicus_), normally sinistral, the right eye is always uppermost.
It is uppermost in 11 reversed examples.

Among the soles this uniformity or monomorphism no longer obtains. In 49
individuals of four species of dextral soles, the left nerve is
uppermost in 24, the right nerve in 25. Among sinistral soles, or
tongue-fishes, in 18 individuals of two species, the left nerve is
uppermost in 13, the right nerve in 5.

Professor Parker concludes from this evidence that soles are not
degenerate flounders, but rather descended from primitive flounders
which still retain the dimorphic condition as to the position of the
optic nerves, a condition prevalent in all bony fishes except the
flounders.

The lack of symmetry among the flounders lies, therefore, deeper than
the matter of the migration of the eye. The asymmetry of the mouth is an
independent trait, but, like the migration of the eye, is an adaptation
to swimming on the side. Each of the various traits of asymmetry may
appear independently of the others.

[Illustration:

  FIG. 428.—Larval Flounder, _Pseudopleuronectes americanus_. (After S.
    R. Williams.)
]

The development of the monomorphic arrangement in flounders Professor
Parker thinks can be accounted for by the principle of natural
selection. In a side-swimming fish the fixity of this trait has a
mechanical advantage. The unmetamorphosed young of the flounder are not
strictly symmetrical, for they possess the monomorphic position of the
optic nerve. The reversed examples of various species of flounders
(these, by the way, chiefly confined to the California fauna) afford
"striking examples of discontinuous variation."

A very curious feature among the flounders is the possession in nine of
the California-Alaskan species of an accessory half-lateral line. This
is found in two different groups, while near relatives in other waters
lack the character. One species in Japan has this trait, which is not
found in any Atlantic species, or in any other flounders outside the
fauna of northern California, Oregon, and Alaska.

=Ancestry of Flounders.=—The ancestry of the flounders is wholly
uncertain. Because, like the codfishes, the flounders lack all
fin-spines, they have been placed by some authors after the
_Anacanthini_, or codfishes, and a common descent has been assumed. Some
writers declare that the flounder is only a codfish with distorted
cranium.

[Illustration:

  FIG. 429.
]

[Illustration:

  FIGS. 429 and 430.—Larval stages of _Platophrys podas_, a flounder of
    the Mediterranean, showing the migration of the eye. (After Emery.)
]

A little study of the osteology of the flounder shows that this
supposition is without foundation. The flounders have thoracic ventrals,
not jugular as in the cod. The tail is homocercal, ending in a large
hypural plate, never isocercal, except in degraded soles, in which it is
rather leptocercal. The shoulder-girdle, with its perforate
hypercoracoid, has the normal perch-like form. The ventral fins have
about six rays, as in the perch, although the first ray is never
spinous. Pseudobranchiæ are developed, these structures being obsolete
in the codfishes. The gills and pharyngeals are essentially as in the
perch.

It is fairly certain that the _Heterosomata_ have diverged from the
early spiny-rayed forms, _Zeoidei_, _Berycoidei_, or _Scombroidei_ of
the Jurassic or Cretaceous, and that their origin is prior to the
development of the great perch stock.

If one were to guess at the nearest relationships of the group, it would
be to regard them as allies of the deep-bodied mackerel-like forms, as
the _Stromateidæ_, or perhaps with extinct Berycoid forms, as
_Platycormus_, having the ventral fins wider than in the mackerel. Still
more plausible is the recent suggestion of Dr. Boulenger that the
extinct genus _Amphistium_ resembles the primitive flounder. But there
is little direct proof of such relation, and the resemblance of larval
flounders to the ribbon-fishes may have equal significance. But the
ribbon-fishes themselves may be degenerate Scombroids. In any case both
ribbon-fishes and flounders find their nearest living relatives among
the _Berycoidei_ or _Zeoidei_, and have no affinity whatever with the
isocercal codfish or with other members of the group called
_Anacanthini_.

[Illustration:

  FIG. 431.—_Platophrys lunatus_ (Linnæus), the Peacock Flounder. Family
    _Pleuronectidæ_. Cuba. (From nature by Mrs. H. C. Nash.)
]

The _Heterosomata_ are found in all seas, always close to the bottom and
swimming with a swift, undulatory motion. They are usually placed in a
single family, but the degraded types known as soles may be regarded as
forming a second family.

=The Flounders: Pleuronectidæ.=—In the flounders, or _Pleuronectidæ_,
the membrane-bones of the head are distinct, the eyes large and well
separated, the mouth not greatly contracted, and the jaws always
provided with teeth. Among the 500 species of flounders is found the
greatest variation in size, ranging in weight from an ounce to 500
pounds. The species found in arctic regions are most degenerate and
these have the largest number of vertebræ and of fin-rays. The halibut
has 50 vertebræ (16 + 34), the craig-flounder 58, while in _Etropus_ and
other tropical forms the number is but 34 (10 + 24). The common
flounders of intermediate geographical range (_Paralichthys dentatus_,
etc.) show intermediate numbers as 40 (10 + 30). The apparent
significance of this peculiar series of fact is given on page 212, Vol.
I. It is, perhaps, related to the greater pressure of natural selection
in the tropics, showing itself in the better differentiation of the
bones and consequently smaller number of the vertebræ.

[Illustration:

  FIG. 432.—Heterocercal tail of young Trout, _Salmo fario_ Linnæus.
    (After Parker & Haswell.)
]

[Illustration:

  FIG. 433.—Homocercal tail of a Flounder, _Paralichthys californicus_.]
]

Fossil flounders are very few and give no clue as to the origin of the
group. In the Eocene and Miocene are remains which have been referred to
_Bothus (Rhombus)_. _Bothus minimus_ is the oldest species known,
described by Agassiz from the Eocene of Monte Bolca. In the Miocene are
numerous other species of _Bothus_, as also tubercles referable to
_Scophthalmus_.

On the testimony of fossils alone the genus _Bothus_, or one of its
allies, would be the most primitive of the group. If it be so, the
simpler structure of the halibut and its relatives is due to
degeneration, which is probable, although their structure has the
suggestion of primitive simplicity, especially in the greater approach
to symmetry in the head and the symmetry in the insertion of the ventral
fins.

[Illustration:

  FIG. 434.—Window-pane, _Lophopsetta maculata_. Virginia.
]

Soles have been found in the later Tertiary rocks. _Solea kirchbergiana_
of the Miocene is not very different from species now extant in southern
Europe. No remains referable to allies of the halibut or plaice are
found in Tertiary rocks, and these relatively simple types must be
regarded as of recent origin.

=The Turbot Tribe: Bothinæ.=—The turbot tribe have the mouth large, the
eyes and color on the left side, and the ventral fins unlike, that of
the left side being extended along the ridge of the abdomen. The species
are found in the warm seas only. They are deeper in body than the
halibut and plaice, and some of them are the smallest of all flounders.
It is probable that these approach most nearly of existing flounders to
the original ancestors of the group.

Perhaps the most primitive genus is _Bothus_, species of which genus are
found in Italian Miocene. The European brill, _Bothus rhombus_, is a
common fish of southern Europe, deep-bodied and covered with smooth
scales.

[Illustration:

  FIG. 435.—Wide-eyed Flounder, _Syacium papillosum_ Linnæus. Pensacola,
    Fla.
]

Very similar but much smaller in size is the half translucent speckled
flounder of our Atlantic coast (_Lophopsetta maculata_), popularly known
as window-pane. This species is too small to have much value as food.
Another species, similar to the brill in technical characters but very
different in appearance, is the turbot, _Scophthalmus maximus_, of
Europe. This large flounder has a very broad body, scaleless but covered
with warty tubercles. It reaches a weight of seventy pounds and has a
high value as a food-fish. There is but one species of turbot and it is
found in Europe only, on sandy bottoms from Norway to Italy. In a turbot
of twenty-three pounds weight Buckland found a roe of five pounds nine
ounces, with 14,311,260 eggs. The young retains its symmetrical
condition for a relatively long period. No true turbot is found in
America and none in the Pacific. Other European flounders allied to the
turbot and brill are _Zeugopterus punctatus_; the European whiff,
_Lepidorhombus whiff-jagonis_; the topknot, _Phrynorhombus regius_; the
lantern-flounder, _Arnoglossus laterna_, and the tongue-fish,
_Eucitharus linguatula_, the last two of small size and feeble flesh.

In the wide-eyed or peacock flounders, _Platophrys podas_ in Europe,
_Platophrys lunatus_, etc., in America, _Platophrys mancus_ in
Polynesia, the eyes in the old males are very far apart, and the changes
due to age and sex are greater than in any other genera. The species of
this group are highly variegated and lie on the sand in the tropical
seas. Numerous small species allied to these abound in the West Indies,
known in a general way as whiffs. The most widely distributed of these
are _Citharichthys spilopterus_ of the West Indies, _Citharichthys
gilberti_ and _Azevia panamensis_ of Panama, _Orthopsetta sordida_ of
California, and especially the common small-mouthed _Etropus crossotus_
found throughout tropical America. Numerous other genera and species of
the turbot tribe are found on the coasts of tropical Asia and Africa,
most of them of small size and weak structure.

[Illustration:

  FIG. 436.—_Etropus crossotus_ Jordan & Gilbert. Cedar Keys, Fla.
]

_Samaris cristatus_ of Asia is the type of another tribe of flounders
and the peculiar hook-jawed _Oncopterus darwini_ of Patagonia represents
still another tribe.

=The Halibut Tribe: Hippoglossinæ.=—In the great halibut tribe the mouth
is large and the ventral fins symmetrical. The arctic and subarctic
species have the eyes and color on the right. Those of the warmer
regions (bastard halibut) have the eyes and color on the left. These
grow progressively smaller in size to the southward, the mouth being
smaller and more feebly armed in southern species.

The largest of the family, and the one commercially of far greatest
importance, is the halibut (_Hippoglossus hippoglossus_). This species
is found on both shores of both oceans, north of about the latitude of
Paris, Boston, Cape Mendocino, and Matsushima Bay in Japan. Its
preference is for off-shore banks of no great depth, and in very many
localities it exists in great abundance, reaching a length of 6 to 8
feet and a weight of 600 pounds. It sometimes ranges well out to sea and
enters deeper waters than the cod. The flesh is firm, white, and of good
quality, although none of the flatfishes have much flavor, the muscles
being mostly destitute of oil. Small halibut, called "chicken halibut,"
are highly esteemed.

Dr. Goode states that the "history of the halibut fishery has been a
peculiar one. At the beginning of the present century these fishes were
exceedingly abundant on George's Banks; since 1850 they have partially
disappeared from this region, and the fishermen have since been
following them to other banks, and since 1874 out into deeper and deeper
water, and the fisheries are now carried on almost exclusively in the
gullies between the off-shore banks and on the outer edges of the banks,
in water 100 to 350 fathoms in depth.

"The halibut with its large mouth is naturally a voracious fish, and
probably would disdain few objects in the way of fresh meat it would
come across. It is said, however, to feed more especially upon crabs and
mollusks in addition to fish. These fish 'they waylay lying upon the
bottom, invisible by reason of their flat bodies, colored to correspond
to the general color of the sand or mud upon which they rest. When in
pursuit of their prey they are active and often come quite to the
surface, especially when in summer they follow the capelin to the shoal
water near the land. They feed upon skates, cod, haddock, menhaden,
mackerel, herring, lobsters, flounders, sculpins, grenadiers, turbot,
Norway haddock, bank-clams, and anything else that is eatable and can be
found in the same waters.' Frequently halibut may be seen chasing
flatfish over the bottom of the water. About Cape Sable their favorite
food seems to be haddock and cusk. A very singular mode of attacking a
cod has been recorded by Captain Collins, an experienced fisherman and
good observer. They often kill their prey by blows of the tail, a fact
which is quite novel and interesting. He has described an instance which
occurred on a voyage home from Sable Island in 1877: 'The man at the
wheel sang out that he saw a halibut flapping its tail about a quarter
of a mile off our starboard quarter. I looked through the spy-glass and
his statement was soon verified by the second appearance of the tail. We
hove out a dory, and two men went with her, taking with them a pair of
gaff-hooks. They soon returned, bringing not only the halibut, which was
a fine one of about seventy pounds weight, but a small codfish which it
had been trying to kill by striking it with its tail. The codfish was
quite exhausted by the repeated blows and did not attempt to escape
after its enemy had been captured. The halibut was so completely engaged
in the pursuit of the codfish that it paid no attention to the dory and
was easily captured.'

"The females become heavy with roe near the middle of the year, and
about July and August are ready to spawn, although 'some fishermen say
that they spawn at Christmas' or 'in the month of January, when they are
on the shoals.' The roe of a large halibut which weighed 356 pounds
weighed 44 pounds, and indeed the 'ovaries of a large fish are too heavy
to be lifted by a man without considerable exertion, being often 2 feet
or more in length.' A portion of the roe 'representing a fair average of
the eggs, was weighed and found to contain 2185 eggs,' and the entire
number would be 2,182,773."

Closely allied to the halibut are numerous smaller forms with more
elongate body. The Greenland halibut, _Reinhardtius hippoglossoides_,
and the closely related species in Japan, _Reinhardtius matsuuræ_,
differ from the halibut most obviously in the straight lateral line. The
arrow-toothed halibut, _Atheresthes stomias_, lives in deeper waters in
the North Pacific. Its flesh is soft, the mouth very large, armed with
arrow-shaped teeth. The head in this species is less distorted than in
any of the others, the upper eye being on the edge of the disk in front
of the dorsal fin. For this reason it has been supposed to be the most
primitive of the living species, but these traits are doubtless elusive
and a result of degeneration.

_Eopsetta jordani_ is a smaller halibut-like fish, common on the coast
of California, an excellent food-fish, with firm white flesh, sold in
San Francisco restaurants under the very erroneous name of "English
sole." Large numbers are dried by the Chinese for export to China. A
similar species, _Hippoglossoides platessoides_, known as the
"sand-dab," is common on both shores of the North Atlantic, and several
related species are found in the North Pacific. _Verasper variegatus_ of
Japan is notable for its bright coloration, the lower side being largely
orange-red.

In the bastard halibuts, _Paralichthys_, the eyes and color are on the
left side. These much resemble the true halibut, but are smaller and
inferior as food, besides differing in details of structure. The
Monterey halibut (_Paralichthys californicus_) is the largest of these,
reaching a weight of sixty pounds. This species and one other from
California (_Xystreurys liolepis_), normally left-sided, differ from all
the other flounders in having the eyes almost as often on the right side
as on the left side, as usual or normal in their type. The summer
flounder (_Paralichthys dentatus_) replaces the Monterey halibut on the
Atlantic Coast, where it is a common food-fish. Farther south it gives
way to the Southern flounder (_Paralichthys lethostigma_) and the Gulf
flounder, _Paralichthys albigutta_. In Japan _Paralichthys olivaceus_ is
equally common, and in western Mexico _Paralichthys sinaloæ_. The
four-spotted flounder of New England, _Paralichthys oblongus_, belongs
to this group. Similar species constituting the genus _Pseudorhombus_
abound in India and Japan.

[Illustration:

  FIG. 437.—Halibut, _Hippoglossus hippoglossus_ Linnæus. Marmot I.,
    Alaska.
]

=The Plaice Tribe: Pleuronectinæ.=—The plaice tribe pass gradually into
the halibut tribe, from which they differ in the small mouth, in which
the blunt teeth are mostly on the blind side. The eyes are on the right
side, the vertebræ are numerous, and the species live only in the cold
seas, none being found in the tropics. In most of the Pacific species
the lateral line has an accessory branch along the dorsal fin. The genus
_Pleuronichthys_, or frog-flounders, has the teeth in bands.
_Pleuronichthys cornutus_ is common in Japan and three species,
_Pleuronichthys cœnosus_ being the most abundant, are found on the coast
of California. Closely related to these is the diamond-flounder,
_Hypsopsetta guttulata_ of California. _Parophrys vetulus_ is a small
flounder of California, so abundant as to have considerable economic
value. _Lepidopsetta bilineata_, larger and rougher, is almost equally
common. It is similar to the mud-dab (_Limanda limanda_) of northern
Europe and the rusty-dab (_Limanda ferruginea_) of New England.

[Illustration:

  FIG. 438.—Wide mouthed Flounder, _Paralichthys dentatus_ (L.). St.
    George I., Md.
]

The plaice, _Pleuronectes platessa_, is the best known of the European
species of this type, being common in most parts of Europe and valued as
food. Closely related to the plaice is a second species of southern
Europe also of small size, _Flesus flesus_, to which the name flounder
is in England especially applied. The common winter flounder of New
England, _Pseudopleuronectes americanus_, is also very much like the
plaice, but with more uniform scales. It is an important food-fish, the
most abundant of the family about Cape Cod. The eel-back flounder,
_Liopsetta putnami_, also of New England, is frequently seen in the
markets. The males of this species have scattered rough scales, while
the females are smooth. The great starry flounder of Alaska,
_Platichthys stellatus_, is the largest of the small-mouthed flounders
and in its region the most abundant. On the Pacific coast from Monterey
to Alaska and across to northern Japan it constitutes half the catch of
flounders. The body is covered with rough scattered scales, the fins are
barred with black. It reaches a weight of twenty pounds. Living in
shallow waters, it ascends all the larger rivers.

An allied species in Japan is _Kareius bicoloratus_, with scattered
scales. _Clidoderma asperrimum_, also of northern Japan, has the body
covered with series of warts.

[Illustration:

  FIG. 439.—Eel-back Flounder, _Liopsetta putnami_ (Gill). Salem, Mass.
]

In deeper water are found the elongate forms known as smear-dab and
flukes. The smear-dab of Europe (_Microstomus kitt_) is rather common in
deep water. Its skin is very slimy, but the flesh is excellent. The same
is true of the slippery sole, _Microstomus pacificus_, of California and
Alaska, and of other species found in Japan. _Glyptocephalus
cynoglossus_, the craig-fluke, or pole-flounder, of the North Atlantic,
is taken in great numbers in rather deep water on both coasts. Its flesh
is much like that of the sole. A similar species (_Glyptocephalus
zachirus_) with a very long pectoral on the right scale is found in
California, and _Microstomus kitaharæ_ in Japan.

=The Soles: Soleidæ.=—The soles (_Soleidæ_) are degraded flounders, the
typical forms bearing a close relation to the plaice tribe, from which
they may be derived. There are three very different groups or tribes of
soles, and some writers have thought that these are independently
derived from different groups of flounders. This fact has been urged as
an argument against the recognition of the _Soleidæ_ as a family
separate from the flounders. If clearly proved, the soles should either
be joined with the flounders in one family or else they should be
divided into two or three, according to their supposed origin.

The soles as a whole differ from the flounders in having the bones of
the head obscurely outlined, their edges covered by scales. The
gill-openings are much reduced, the eyes small and close together, the
ventral fins often much reduced, and sometimes the pectoral or caudal
also. The mouth is very small, much twisted, and with few teeth.

[Illustration:

  FIG. 440.—Starry Flounder, _Platichthys stellatus_ (Pallas). Alaska.
]

The species of sole, about 150 in number, abound on sandy bottoms in the
warm seas along the continents, very few being found about the Oceanic
Islands. The three subfamilies, or tribes, may be designated as broad
soles, true soles, and tongue-fishes.

=The Broad Soles: Achirinæ.=—The American soles (_Achirinæ_), or broad
soles, resemble the smaller members of the turbot tribe of flounders,
having the ventral fin of the eyed side extended along the ridge of the
abdomen. The eyes and color are, however, on the right side. The eyes
are separated by a narrow interorbital ridge. In most of these forms the
body is broad and covered with rough scales. The species are mostly less
than six inches long, and nearly all are confined to the warmer parts of
America, many of them ascending the rivers. A very few (_Aseraggodes_,
_Pardachirus_) are found in Japan and China. Some are scaleless and some
have but a single small gill-opening on the blind side. The principal
genus is _Achirus_. _Achirus fasciatus_, the common American sole, or
hog-choker, is abundant from Boston to Galveston. _Achirus lineatus_ and
other species are found in the West Indies and on the west coast of
Mexico. Almost all the species of _Achirus_ are banded with black and
the pectorals are very small or wanting altogether. All these species
are practically useless as food from their very small size.

[Illustration:

  FIG. 441.—Hog-choker Sole, _Achirus lineatus_ (L.). Potomac River.
]

=The European Soles (Soleinæ).=—The European soles are more elongate in
form, with the ventral fins narrow and not extended along the ridge of
the abdomen. The eyes are on the right side with no bony ridge between
them. No species of this type is certainly known from American waters,
although numerous in Europe and Asia. The species have much in common
with the plaice tribe of flounders and may be derived from the same
stock. One species, as above noted, is found in the Miocene.

The common sole of Europe, _Solea solea_, is one of the best of
food-fishes, reaching a length, according to Dr. Gill, of twenty-six
inches and a weight of nine pounds. As usually seen in the markets it
rarely exceeds a pound. It is found from Norway to Italy, and when
properly cooked is very tender and delicate, superior to any of the
flounders. According to Dr. Francis Day, it appears to prefer sandy or
gravelly shores, but is rather uncertain in its migrations, for,
although mostly appearing at certain spots almost at a given time, and
usually decreasing in numbers by degrees, in other seasons they
disappear at once, as suddenly as they arrive. Along the British
seacoast they retire to the deep as frosts set in, revisiting the
shallows about May if the weather is warm, their migrations being
influenced by temperature. The food of the sole is to a considerable
extent molluscous, but it is also said to eat the eggs and fry of other
fishes and sea-urchins.

The spawning season is late in the year and during the spring months.
The ova are in moderate number; a sole of one pound weight has,
according to Buckland, about 134,000 eggs. The newly hatched, according
to Dr. Day, do not appear to be commonly found so far out at sea as some
other species. They enter into shallow water at the edge of the tide and
are very numerous in favorable localities.

As is well known, the sole is one of the most esteemed of European
fishes. In the words of Dr. Day, "the flesh of this fish is white, firm,
and of excellent flavor, those from the deepest waters being generally
preferred. Those on the west coast and to the south are larger, as a
rule, than those towards the north of the British islands. In addition
to its use as food, it is available for another purpose. The skin is
used for fining coffee, being a good substitute for isinglass, and also
as a material for artificial baits.

"The markets are generally supplied by the trawl. The principal English
trawling-ground lies from Dover to Devonshire. They may be taken by
spillers, but are not commonly captured with hooks; it is suggested that
one reason may be that spillers are mostly used by day, whereas the sole
is a night feeder. They are sometimes angled for with the hook, baited
with crabs, worms, or mollusks; the most favorable time for fishing is
at night, after a blow, when the water is thick, while a land breeze
answers better than a sea breeze."

Several smaller species of sole are found in Europe. In Japan _Zebrias
zebra_, black-banded, and _Usinosita japonica_, known as _Usinóshita_,
or cow's tongue, are common. Farther south are numerous species of
_Synaptura_ and other genera peculiar to the Indian and Australian
regions.

=The Tongue-fishes: Cynoglossinæ.=—The tongue-fishes are soles having
the eyes on the left side not separated by a bony ridge, the two being
very small and apparently in the same socket. The body is lanceolate,
covered usually with rough scales, and as often with two or three
lateral lines as with one. The species are mostly Asiatic. _Cynoglossus
robustus_ and other species are found in Japan, and in India are many
others belonging to _Cynoglossus_ and related genera. The larger species
are valued as food. The single European species _Symphurus nigrescens_,
common in the Mediterranean, is too small to have any value. _Symphurus
plagiusa_, the tongue-fish of our coast, is common on our sandy shores
from Cape Hatteras southward. _Symphurus plagusia_, scarcely different,
replaces it in the West Indies. _Symphurus atricandus_ is found in San
Diego Bay, and numerous other species of no economic importance find
their place farther south.

[Illustration:

  FIG. 442.—_Symphurus plagiusa_ (L.). Beaufort, N. C.
]



                             CHAPTER XXVIII
                           SUBORDER JUGULARES


=THE Jugular-fishes.=—In all the families of spiny-rayed fishes, as
ranged in order in the present work, from the _Berycidæ_ to the
_Soleidæ_, the ventrals are thoracic in position, the pelvis, if
present, being joined to the shoulder-girdle behind the symphysis of the
clavicles so that the ventral fin falls below or behind the pectoral
fin. To this arrangement the families of _Bembradidæ_ and _Pinguipedidæ_
offer perhaps the only exceptions.

In all the families which precede the _Berycidæ_ in the linear series
adopted in this work, the ventral fins when present are abdominal, the
pelvis lying behind the clavicles and free from them as in the sharks,
the reptiles, and all higher vertebrates.

In all the families remaining for discussion, the ventrals are brought
still farther forward to a point distinctly before the pectorals. This
position is called jugular (Lat. _jugulum_, throat).

The fishes with jugular ventrals we here divide into six groups, orders,
and suborders: _Jugulares_, _Haplodoci_, _Xenopterygii_, _Anacanthini_,
_Opisthomi_, and _Pediculati_. The last two groups, and perhaps the
_Anacanthini_ also, may well be considered as distinct orders, being
more aberrant than the others.

For the most primitive and at the same time most obscurely defined of
these groups we may retain the term applied by Linnæus to all of them,
the name _Jugulares_. This group includes those jugular-fishes in which
the position of the gills, the structure of the skull, and the form of
the tail are essentially as in ordinary fishes. It is an extremely
diversified and perhaps unnatural group, some of its members resembling
_Opisthognathidæ_ and _Malacanthidæ_, others suggesting the mailed-cheek
fishes, and still others more degenerate. The fishes having the fins
thus placed were long ago set apart by Linnæus, under the name of
"Jugulares," _Callionymus_ being the genus first placed by him in this
group. Besides their anterior insertion, the ventrals in the _Jugulares_
are more or less reduced in size, the rays being usually but not always
less than I, 5 in number and more often reduced to one or two, or even
wholly lost.

In general, the jugular fishes are degenerate as compared with the
perch-like forms, but in certain regards they are often highly
specialized. The groups showing this character are probably related one
to another, but in some cases this fact is not clearly shown. In most of
the jugular-fishes the shoulder-girdle shows some change or distortion.
The usual foramen in the hypercoracoid is often wanting or relegated to
the interspace between the coracoids, and the arrangement of the
actinosts often deviates from that seen in the perciform fishes.

=The Weevers: Trachinidæ.=—Of the various families the group of weevers,
_Trachinidæ_, most approaches the type of ordinary fishes. In the words
of Dr. Gill, these fishes are known by "an elongated body attenuated
backward from the head, compressed, oblong head, with the snout very
short, a deeply cleft, oblique mouth, and a long spine projecting
backward from each operculum and strengthened by extension on the
surface of the operculum, as a keel. The dorsal fins are distinct, the
first composed of strong, pungent spines radiating from a short base and
about six or seven in number. The second dorsal and anal are very long.
The pectorals have the lower rays unbranched, and the ventrals are in
advance of the pectorals, and have each a spine and five rays. The
species of this family are mostly found along the European and western
African coast; but singularly enough a species closely related to the
Old World form is found on the coast of Chile. None have been obtained
from the intermediate regions or from the American coast. Two species
are found in England, and are known under the name of the greater weever
(_Trachinus draco_), about twelve inches long, and the lesser weever
(_Trachinus vipera_), about six inches long. They are perhaps the most
dreaded of the smaller English fishes. The formidable opercular spines
are weapons of defense, and when seized by the fisherman the fish is apt
to throw its head in the direction of the hand and lance a spine into
it. The pungent dorsal spines are also defensive. Although without a
poison gland, such as some fishes distantly related have at the base of
the spines, they cause very severe wounds, and death may occur from
tetanus. They are therefore divested of both opercular and dorsal spines
before being exposed for sale. The various popular names which the
weevers enjoy, in addition to their general designation, mostly refer to
the armature of the spines, or are the result of the armature; such are
adder-fish, stingfish, and sting-bull."

No species of _Trachinidæ_ is known from North America or from Asia. In
these fishes, as Dr. Boulenger has lately shown, the hypercoracoid is
without foramen, the usual perforation lying between this bone and the
hypercoracoid. A similar condition exists in the _Anacanthini_, or
codfishes, but it seems to have been developed independently in the two
groups. In the relatives of the _Trachinidæ_ the position of this
foramen changes gradually, moving by degrees from its usual place to the
lower margin of the hypercoracoid. Species referred to _Trachinus_ are
recorded from the Miocene as well as _Trachinus_.

The extinct group of _Callipterygidæ_ found in the Eocene of Monte Bolca
seems allied to the _Trachinidæ_. It has the dorsal fin continuous, the
spines small, the soft rays high; the scales are very small or wanting.
_Callipteryx speciosus_ and _C. recticandus_ are the known species.

=The Nototheniidæ.=—In the family of _Nototheniidæ_ the foramen is also
wanting or confluent with the suture between the coracoids. To this
family belong many species of the Antarctic region. These are elongate
fishes with ctenoid scales and a general resemblance to small
_Hexagrammidæ_. In most of the genera there is more than one lateral
line. These species are the antipodes of the _Cottidæ_ and
_Hexagrammidæ_; although lacking the bony stay of the latter, they show
several analogical resemblances and have very similar habits.

The _Harpagiferidæ_, naked, with the opercle armed with spines, and
resemble sculpins even more closely than do the _Nototheniidæ_.
_Harpagifer_ is found in Antarctic seas, and the three species of
_Draconetta_ in the deeper waters of the North Atlantic and Pacific.
These little fishes resemble _Callionymus_, but the opercle, instead of
the preopercle, bears spines. The _Bovichthyidæ_ of New Zealand are also
sculpin-like and perhaps belong to the same family. Dr. Boulenger places
all these Antarctic forms with the foramen outside the hypercoracoid in
one family, _Nototheniidæ_. Several deep-sea fishes of this type have
been lately described by Dr. Louis Dollo and others from the Patagonian
region. One of these forms, _Macrias amissus_, lately named by Gill and
Townsend, is five feet long, perhaps the largest deep-sea fish known.
The family of _Percophidæ_, from Chile, is also closely allied to these
forms, the single species differing in slight respects of osteology.

[Illustration:

  FIG. 443.—_Pteropsaron evolans_ Jordan & Snyder. Sagami Bay, Japan.
]

Closely related to the family of _Nototheniidæ_ and perhaps scarcely
distinct from it is the small family of _Pteropsaridæ_, which differs in
having but one lateral line and the foramen just above the lower edge of
the hypercoracoid. The numerous species inhabit the middle Pacific, and
are prettily colored fishes, looking like gobies. _Pteropsaron_ is a
Japanese genus, with high dorsal and anal fins; _Parapercis_ is more
widely diffused. _Osurus schauinslandi_ is one of the neatest of the
small fishes of Hawaii. Several species of _Parapercis_ and _Neopercis_
occur in Japan and numerous others in the waters of Polynesia.
_Pseudeleginus majori_ of the Italian Miocene must belong near
_Parapercis_.

The _Bathymasteridæ_, or ronquils, are perhaps allied to the
_Nototheniidæ_; they resemble the _Opisthognathidæ_, but the jaws are
shorter and they have a large number of vertebræ as befits their
northern distribution. _Ronquilus jordani_ is found in Puget Sound and
_Bathymaster signatus_ in Alaska. The ventral rays are I, 5, and the
many-rayed dorsal has a few slender spines in front.

[Illustration:

  FIG. 444.—_Bathymaster signatus_ Cope. Shumagin Is., Alaska.
]

=The Leptoscopidæ.=—The _Leptoscopidæ_ of New Zealand resemble the
weevers and star-gazers, but the head is unarmed, covered by thin skin.

=The Star-gazers: Uranoscopidæ.=—The _Uranoscopidæ_, or star-gazers,
have the head cuboid, mostly bony above, the mouth almost vertical, the
lips usually fringed, and the eyes on the flat upper surface of the
head. The spinous dorsal is short and may be wanting. The hypercoracoid
has a foramen, and the body is naked or covered with small scales. The
appearance is eccentric, like that of some of the _Scorpænidæ_, but the
anatomy differs in several ways from that of the mailed-cheek fishes.

The species inhabit warm seas, and the larger ones are food-fishes of
some importance. One species, _Uranoscopus scaber_, abounds in the
Mediterranean. _Uranoscopus japonicus_ and other species are found in
Japan. _Astroscopus y-græcum_ is the commonest species on our Atlantic
coast. The bare spaces on the top of the head in this species yield
vigorous electric shocks. Another American species is _Astroscopus
guttatus_. In Japan and the East Indies the forms are more numerous and
varied. _Ichthyscopus lebeck_, with a single dorsal, is a fantastic
inhabitant of the seas of Japan, and _Anema monopterygium_ in New
Zealand.

_Uranoscopus peruzzii_, an extinct star-gazer, has been described from
the Pliocene of Tuscany.

[Illustration:

  FIG. 445.—A Star-gazer _Ariscopus iburius_ Jordan & Snyder. Iburi,
    Japan.
]

=The Dragonets: Callionymidæ.=—Remotely allied to the _Uranoscopidæ_ is
the interesting family of dragonets, or _Callionymidæ_. These are small
scaleless fishes with flat heads, the preopercle armed with a strong
spine, the body bearing a general resemblance to the smaller and
smoother _Cottidæ_. The gill-openings are very small, the ventral fins
wide apart. The colors are highly variegated, the fins are high, often
filamentous, and the sexes differ much in coloration and in the
development of the fins. The species are especially numerous on the
shores of Japan, where _Callionymus valenciennesi_, _Callionymus
beniteguri_, and _Calliurichthys japonicus_ are food-fishes of some
slight importance. Others are found in the East Indies, and several
large and handsome forms are taken in the Mediterranean. _Callionymus
draco_, the dragonet, or "sculpin," reaches the coast of England. In
America but three species have been taken. These are dredged in deep
water in the East Indies. In other parts of the world these fantastic
little creatures are shore-fishes, creeping about in the shallow bays.
Species of _Synchiropus_, colored like the coral sands, abound in the
Polynesian coral reefs.

A fossil species of _Callionymus_ (_C. macrocephalus_) are found in the
Miocene of Croatia.

The family of _Rhyacichthyidæ_ is a small group of Asiatic fishes allied
to the _Callionymidæ_, but less elongate and differing in minor details.
They are found not in the sea, but in mountain streams. _Rhyacichthys_
(formerly called by the preoccupied name _Platyptera_) is the principal
genus.

[Illustration:

  FIG. 446.—Star-gazer, _Astroscopus guttatus_ Abbott. (From life by Dr.
    R. W. Shufeldt.)
]

The _Trichonontidæ_, with wide gill-openings and cycloid scales, are
also related to the _Callionymidæ_. The species are few, small, and
confined to the Indian and Australian seas. Another small family closely
related to this is the group of _Hemerocœtidæ_ of the same region.

=The Dactyloscopidæ.=—In this and the preceding families of jugular
fishes the ventral rays remain I, 5, as in the typical thoracic forms.
In most of the families yet to be described the number is I, 3, a
character which separates the little fishes of the family of
_Dactyloscopidæ_ from the _Uranoscopidæ_ and _Leptoscopidæ_.
_Dactyloscopus tridigitatus_ is a small fish of the coral sands of Cuba.
The other species of this family are found mostly in the West Indies and
on the west coast of Mexico. Several genera, _Myxodagnus_, _Gillellus_,
_Dactylagnus_, etc., are recognized. In the structure of the
shoulder-girdle these species diverge from the star-gazers, approaching
the blennies, and their position is intermediate between _Trachinidæ_
and _Blenniidæ_.



                              CHAPTER XXIX
                        THE BLENNIES: BLENNIIDÆ


[Illustration:

  FIG. 447.—Sarcastic Blenny, _Neoclinus satiricus_ Girard. Monterey.
]

THE great family of blennies, _Blenniidæ_, contains a vast number of
species with elongate body, numerous dorsal spines, without suborbital
stay or sucking-disk, and the ventrals jugular, where present, and of
one spine and less than five soft rays. Most of them are of small size,
living about rocks on the sea-shores of all regions. In general they are
active fishes, of handsome but dark coloration, and in the different
parts of the group is found great variety of structure. The tropical
forms differ from those of arctic regions in the much shorter bodies and
fewer vertebræ. These forms are most like ordinary fishes in appearance
and structure and are doubtless the most primitive. Of the five hundred
known species of blennies, we can note only a few of the most prominent.
To _Clinus_ and related genera belong many species of the warm seas,
scaly and ovoviviparous, at least for the most part. The largest of
these is the great kelpfish of the coast of California, _Heterostichus
rostratus_, a food-fish of importance, reaching the length of two feet.
Others of this type scarcely exceed two inches. _Neoclinus satiricus_,
also of California, is remarkable for the great length of the upper jaw,
which is formed as in _Opisthognathus_. Its membranes are brightly
colored, being edged with bright yellow. _Gibbonsia elegans_ is the
pretty "señorita" of the coralline-lined rock-pools of California.
_Lepisoma nuchipinne_, with a fringe of filaments at the nape, is very
abundant in rock-pools of the West Indies. The species of
_Auchenopterus_ abound in the rock-pools of tropical America. These are
very small neatly colored fishes with but one soft ray in the long
dorsal fin. Species of _Tripterygion_, _Myxodes_, _Cristiceps_, and
other genera abound in the South Pacific.

[Illustration:

  FIG. 448.—Kelp Blenny, _Gibbonsia evides_ Jordan & Gilbert. San Diego.
]

[Illustration:

  FIG. 449.—_Blennius cristatus_ L. Florida.
]

In _Blennius_ and its relatives the body is scaleless and the slender
teeth are arranged like the teeth of a comb. In most species long,
fang-like posterior canines are developed in the jaws. _Blennius_ is
represented in Europe by many species, _Blennius galerita_, _ocellaris_,
and _basiliscus_ being among the most common. Certain species inhabit
Italian lakes, having assumed a fresh-water habit. The numerous American
species mostly belong to other related genera, _Chasmodes bosquianus_
being most common. _Blennius yatabei_ abounds in Japan. In
_Petroscirtes_ and its allies the gill-openings are much restricted. The
species are mainly Asiatic and Polynesian and are very prettily colored.
_Petroscirtes elegans_ and _P. trossulus_ adorn the Japanese rock-pools
and others, often deep blue in color, abound in the coral reefs of
Polynesia.

[Illustration:

  FIG. 450.—Rock-skipper, _Alticus atlanticus_. San Cristobal, Lower
    Cal.
]

[Illustration:

  FIG. 451.—Lizard-skipper, _Alticus saliens_ (Forster). A blenny which
    lies out of water on lava rocks, leaping from one to another with
    great agility. From nature; specimen from Point Distress, Tutuila
    Island, Samoa. (About one-half size.)
]

[Illustration:

  FIG. 452.—_Emblemaria atlantica_ Jordan. Pensacola, Fla.
]

The rock-skippers (Salarias, Alticus, etc.) are herbivorous, with
serrated teeth set loosely in the jaws. These live in the rock-pools of
the tropics and leap from rock to rock when disturbed with the agility
of lizards. They are dusky or gray in color with handsome markings. One
of them, _Erpichthys_ or _Alticus saliens_ in Samoa, lives about lava
rocks between tide-marks, and at low tide remains on the rocks, over
which it runs with the greatest ease and with much speed, its movements
being precisely like those of _Periophthalmus_. As in the species of the
latter genus, otherwise wholly different, this _Alticus_ has short
ventral fins padded with muscle.

[Illustration:

  FIG. 453.—_Scartichthys enosimæ_ Jordan & Snyder, a fish of the
    rock-pools of the sacred island of Enoshima, Japan. Family
    _Blenniidæ_.
]

_Erpichthys atlanticus_ is found in abundance on both coasts of tropical
America. Many species abound in Polynesia and in both Indies. _Salarias
enosimæ_ lives in the clefts of lava rocks on the shores of Japan.
_Ophioblennius_ (_webbi_) is remarkable for its strong teeth,
_Emblemaria_ (_nivipes_, _Atlantica_) for its very high dorsal. Many
other genera allied to _Blennius_, _Clinus_, and _Salarias_ abound in
the warm seas.

[Illustration:

  FIG. 454.—_Zacalles bryope_ Jordan & Snyder. Misaki, Japan.
]

[Illustration:

  FIG. 455.—_Bryostemma tarsodes_ Jordan & Snyder. Unalaska.
]

[Illustration:

  FIG. 456.—_Exerpes asper_ Jenkins & Evermann. Guaymas, Mexico. Family
    _Blenniidæ_.
]

=The Northern Blennies: Xiphidiinæ, Stichæiniæ, etc.=—The blennies of
the north temperate and arctic zones have the dorsal fin more elongate,
the dorsal fin usually but not always composed entirely of spines. The
scales are small and the ventral fins generally reduced in size. These
are divided by Dr. Gill into several distinct families, but the groups
recognized by him are subject to intergradations.

[Illustration:

  FIG. 457.—Gunnel, _Pholis gunnellus_ (L.). Gloucester, Mass.
]

[Illustration:

  FIG. 458.—_Xiphistes chirus_ Jordan & Gilbert. Amchitka I., Alaska.
]

_Chirolophis_ (_ascanii_) of north Europe is remarkable for the tufted
filaments on the head. These are still more developed in _Bryostemma_ of
the North Pacific, _Bryostemma polyactocephalum_ and several other
species being common from Puget Sound to Japan. _Apodichthys_
(_flavidus_) of California is remarkable for a large quill-shaped anal
spine and for the great variation in color, the hue being yellow,
grass-green, or crimson, according to the color of the algæ about it.
There is no evidence, however, that the individual fish can change its
color, and these color forms seem to be distinct races within the
species. _Xererpes fucorum_ of California lies quiescent in the seaweed
(_Fucus_) after the tide recedes, its form, color, and substance seeming
to correspond exactly with those of the stems of algæ. _Pholis
gunnellus_ is the common gunnel (gunwale), or butter-fish, of both
shores of the North Atlantic, with numerous allies in the North Pacific.
Of these, _Enedrias nebulosus_, the ginpo, or silver-tail, is especially
common in Japan. _Xiphidion_ and _Xiphistes_ of the California coast,
and _Dictyosoma_ of Japan, among others, are remarkable for the great
number of lateral lines, these extending crosswise as well as
lengthwise. _Cebedichthys violaceus_, a large blenny of California, has
the posterior half of the dorsal made of soft rays. _Opisthocentrus_ of
Siberia and north Japan has the dorsal spines flexible, only the
posterior ones being short and stiff. The snake-blennies (_Lumpenus_),
numerous in the far North, are extremely slender, with well-developed
pectorals and ventrals. _Lumpenus lampetræformis_ is found on both
shores of the Atlantic. In _Stichæus_ a lateral line is present. There
is none in _Lumpenus_, and in _Ernogrammus_ and _Ozorthe_ there are
three. All these are elongate fishes, of some value as food and
especially characteristic of the Northern seas. Fossil blennies are
almost unknown. _Pterygocephalus paradoxus_ of the Eocene resembles the
living _Cristiceps_, a genus which differs from _Clinus_ in having the
first few dorsal spines detached, inserted on the head. The first spine
alone in _Pterygocephalus_ is detached and is very strong. A species
called _Clinus gracilis_ is described from the Miocene near Vienna,
_Blennius fossilis_ from the Miocene of Croatia, and an uncertain
_Oncolepis isseli_ from Monte Bolca. The family is certainly one of the
most recent in geologic times. The family of _Blenniidæ_, as here
recognized, includes a very great variety of forms and should perhaps be
subdivided into several families, as Dr. Gill has suggested. At present
there is, however, no satisfactory basis of division known.

[Illustration:

  FIG. 459.—_Ozorthe dictyogramma_ (Hertzenstein), a Japanese blenny
    from Hakodate: showing increased number of lateral lines, a trait
    characteristic of many fishes of the north Pacific.
]

[Illustration:

  FIG. 460.—_Stichæus punctatus_ Fabricius. St. Michael, Alaska.
]

=The Quillfishes: Ptilichthyidæ.=—The _Ptilichthyidæ_, or quillfishes,
are small and slender blennies of the North Pacific, with very numerous
fin-rays. _Ptilichthys goodei_ has 90 dorsal spines and 145 soft rays.
Another group of very slender naked blennies is the small family of
_Xiphasiidæ_ from the South Pacific. The jaws have excessively long
canines; there are no ventral fins. The dorsal fin is very high and the
caudal ends in a long thread.

[Illustration:

  FIG. 461.—_Bryostemma otohime_ Jordan & Snyder. Hakodate, Japan.
    Family _Blenniidæ_.
]

[Illustration:

  FIG. 462.—Quillfish, _Ptilichthys goodei_ Bean. Unalaska.
]

[Illustration:

  FIG. 463.—_Blochius longirostris_ Volta, restored. Upper Eocene of
    Monte Bolca. (After Woodward.)
]

=The Blochiidæ.=—Of doubtful relationship is the extinct family of
_Blochiidæ_. In this group the body is elongate, covered with keeled
plates imbricated like shingles. The dorsal is composed of many slender
spines, and the vertebræ much elongate. In _Blochius longirostris_
(Monte Bolca Eocene) has very long jaws, lined with small teeth. Zittel
regards the family as allied to the _Belonorhynchidæ_, but the
prolongation of the jaws may be a character of analogy merely. Woodward
places it next to the _Blenniidæ_, supposing it to have small and
jugular ventral fins. But as the presence of ventral fins is uncertain,
the position of the family cannot be ascertained and it may really
belong in the neighborhood of _Ammodytes_. The dorsal rays are figured
by Woodward as simple.

[Illustration:

  FIG. 464.—_Xiphasia setifera_ Swainson. India. (After Day.)
]

=The Patæcidæ etc.=—The _Patæcidæ_ are blenny-like fishes of Australia,
having the form of _Congriopus_, the spinous dorsal being very high and
inserted before the eyes, forming a crest. _Patæcus fronto_ is not rare
in South Australia. The _Gnathanacanthidæ_ is another small group of
peculiar blennies from the Pacific. The _Acanthoclinidæ_ are small
blennies of New Zealand with numerous spines in the anal fin.
_Acanthoclinus littoreus_ is the only known species.

=The Gadopsidæ, etc.=—The family of _Gadopsidæ_ of the rivers of New
Zealand and southern Australia consists of a single species, _Gadopsis
marmoratus_, resembling the scaly blennies called _Clinus_, but with
long ventrals of a single ray, and three spines in the anal fin besides
other peculiarities. The species is locally very common and with various
other fishes in regions where true trout are unknown, it is called
"trout."

The _Cerdalidæ_ are small band-shaped blennies of the Pacific coast of
Panama. The slender dorsal spines pass gradually into soft rays. Three
species are known.

[Illustration:

  FIG. 465.—Wrymouth, _Cryptacanthodes maculatus_. New York.
]

The wrymouths, or _Cryptacanthodidæ_, are large blennies of the northern
seas, with the mouth almost vertical and the head cuboid. The wrymouth
or ghostfish, _Cryptacanthodes maculatus_, is frequently taken from Long
Island northward. It is usually dusky in color, but sometimes pure
white. Other genera are found in the north Pacific.

=The Wolf-fishes: Anarhichadidæ.=—The wolf-fishes (_Anarhichadidæ_) are
large blennies of the northern seas, remarkable for their strong teeth.
Those in front are conical canines. Those behind are coarse molars. The
dorsal is high, of flexible spines. The species are large, powerful,
voracious fishes, known as wolf-fishes. _Anarhichas lupus_ is the common
wolf-fish of the north Atlantic, reaching a length of four to six feet,
the body marked by dark cross-bands. Other similar species are found
both in the north Pacific and north Atlantic. _Anarhichas lepturus_,
plain brown in color, is common about the Aleutian Islands.

[Illustration:

  FIG. 466.—Wolf-fish, _Anarhichas lupus_ (L.). Georges Bank.
]

[Illustration:

  FIG. 467.—Skull of _Anarrhichthys ocellatus_ Ayres.
]

In the wolf-eel (_Anarrhichthys ocellatus_) of the coast of California,
the head is formed as in _Anarhichas_ but the body is band-shaped, being
drawn out into a very long and tapering tail. This species, which is
often supposed to be a "sea-serpent," sometimes reaches a length of
eight feet. It is used for food. It feeds on sea-urchins and
sand-dollars (_Echinarachinius_) which it readily crushes with its
tremendous teeth.

The skull of a fossil genus, _Laparus_ (_alticeps_), with a resemblance
to _Anarhichas_, is recorded from the Eocene of England.

=The Eel-pouts: Zoarcidæ.=—The remaining blenny-like forms lack fin
spines, agreeing in this respect with the codfishes and their allies. In
all of the latter, however, the hypercoracoid is imperforate, the
pseudobranchiæ are obsolete, and the tail isocercal. The forms allied to
_Zoarces_ and _Ophidion_, and which we may regard as degraded blennies,
have homocercal (rarely leptocercal) tails, generally but not always
well-developed pseudobranchiæ and the usual foramen in the
hypercoracoid.

[Illustration:

  _Fig. 463._—Eel-pout, _Zoarces anguillaris_ Peck. Eastport, Me.
]

The _Zoarcidæ_, or eel-pouts, have the body elongate, naked, or covered
with small scales, the dorsal and anal of many soft rays and the
gill-openings confined to the side. Most of the species live in rather
deep water in the Arctic and Antarctic regions. _Zoarces viviparus_, the
"mother of eels," is a common fish of the coasts of northern Europe. In
the genus _Zoarces_, the last rays of the dorsal are short and stiff,
like spines. The species are viviparous; the young being eel-like in
form, the name "mother of eels" has naturally arisen in popular
language. The American eel-pout, sometimes called mutton-fish, _Zoarces
anguillaris_, is rather common north of Cape Cod, and a similar species,
_Zoarces elongatus_, is found in northern Japan. _Lycodopsis pacifica_,
without spines in the dorsal, replaces _Zoarces_ in California. The
species of _Lycodes_, without spines in the dorsal, and with teeth on
the vomer and palatines, are very abundant in the northern seas,
extending into deep waters farther south. _Lycodes reticulatus_ is the
most abundant of these fishes, which are valued chiefly by the Esquimaux
and other Arctic races of people. Numerous related genera are recorded
from deep-sea explorations, and several others occur about Tierra del
Fuego. _Gymnelis_, small, naked species brightly colored, is represented
by _Gymnelis viridis_ in the Arctic and by _Gymnelis pictus_ about Cape
Horn.

[Illustration:

  FIG. 469.—Eel-pout, _Lycodes reticulatus_ Reinhardt. Banquereau.
]

[Illustration:

  FIG. 470.—_Lycenchelys verrilli_ (Goode & Bean). Chebucto, Nova
    Scotia.
]

[Illustration:

  FIG. 471.—_Scytalina cerdale_ Jordan & Gilbert. Straits of Fuca.
]

The family of _Scytalinidæ_ contains a single species, _Scytalina
cerdale_, a small snake-shaped fish which lives in wet gravel between
tide-marks, on Waada Island near Cape Flattery in Washington, not having
yet been found elsewhere. It dives among the wet stones with great
celerity, and can only be taken by active digging.

To the family of _Congrogadidæ_ belong several species of eel-shaped
blennies with soft rays only, found on the coasts of Asia. Another small
family, _Derepodichthyidæ_, is represented by one species, a scaleless
little fish from the shores of British Columbia.

The _Xenocephalidæ_ consist of a single peculiar species, _Xenocephalus
armatus_, from the island of New Ireland. The head is very large,
helmeted with bony plates and armed with spines. The body is short and
slender, the ventrals with five rays, the dorsal and anal short.

=The Cusk-eels: Ophidiidæ.=—The more important family of _Ophidiidæ_, or
cusk-eels, is characterized by the extremely anterior position of the
ventral fins, which are inserted at the throat, each one appearing as a
long forked barbel. The tail is leptocercal, attenuate, the dorsal and
anal confluent around it. _Ophidion barbatum_ and _Rissola rochei_ are
common in southern Europe. _Rissola marginata_ is the commonest species
on our Atlantic coast, and _Chilara taylori_ in California. Other
species are found farther south, and still others in deep water.
_Genypterus_ contains numerous species of the south Pacific, some of
which reach the length of five feet, forming a commercial substitute for
cod. _Genypterus capensis_ is the klipvisch of the Cape of Good Hope,
and _Genypterus australis_ the "Cloudy Bay cod" or "rock ling" of New
England. Another large species, _Genypterus maculatus_, occurs in Chile.
A few fragments doubtfully referred to _Ophidion_ and _Fierasfer_ occur
in the Eocene and later rocks. The _Lycodapodidæ_ contain a few small,
scaleless fishes (_Lycodapus_) dredged in the north Pacific.

[Illustration:

  FIG. 472.—Cusk-eel, _Rissola marginata_ (De Kay). Virginia.
]

[Illustration:

  FIG. 473.—_Lycodapus dermatinus_ Gilbert. Lower California.
]

=Sand-lances: Ammodytidæ.=—Near the _Ophidiidæ_ are placed the small
family of sand-lances (_Ammodytidæ_). This family comprises small,
slender, silvery fishes, of both Arctic and tropical seas, living along
shore and having the habit of burying themselves in the sand under the
surf in shallow water. The jaws are toothless, the body scarcely scaly
and crossed by many cross-folds of skin, the many-rayed dorsal fin is
without spines, and the ventral fins when present are jugular. The
species of the family are very much alike. From their great abundance
they have sometimes much value as food, more perhaps as bait, still more
as food for salmon and other fishes, from which they escape by plunging
into the sand. Sometimes a falling tide leaves a sandy beach fairly
covered with living "lants" looking like a moving foam of silver.
_Ammodytes tobianus_ is the sand-lance or lant of northern Europe.
_Ammodytes americanus_, scarcely distinguishable, replaces it in
America; and _Ammodytes personatus_ in California, Alaska, and Japan.
This is a most excellent pan fish, and the Japanese, who regard little
things, value it highly.

[Illustration:

  FIG. 474.—Sand-lance, _Ammodytes americanus_ De Kay. Nantucket.
]

[Illustration:

  FIG. 475.—_Embolichthys mitsukurii_ (Jordan & Evermann). Formosa.
]

In the genus _Hyperoplus_ there is a large tooth on the vomer. In the
tropical genera there is a much smaller number of vertebræ and the body
is covered with ordinary scales instead of delicate, oblique cross-folds
of skin. These tropical species must probably be detached from the
_Ammodytidæ_ to form a distinct family, _Bleekeriidæ_. _Bleekeria
kallolepis_ is found in India, _Bleekeria gilli_ is from an unknown
locality, and the most primitive species of sand-lance, _Embolichthys
mitsukurii_, occurs in Formosa. In this species, alone of the
sand-lances, the ventral fins are retained. These are jugular in
position, as in the _Zoarcidæ_, and the rays are I, 3. The discovery of
this species makes it necessary to separate the _Ammodytidæ_ and
_Bleekeriidæ_ widely from the _Percesoces_, and especially from the
extinct families of _Crossognathidæ_ and _Cobitopsidæ_ with which its
structure in other regards has led Woodward, Boulenger, and the present
writer to associate it.

Although an alleged sand-lance, _Rhynchias septipinnis_, with ventral
fins abdominal, was described a century ago by Pallas, no one has since
seen it, and it may not exist, or, if it exists, it may belong among the
_Percesoces_. The relation of _Ammodytes_ to _Embolichthys_ is too close
to doubt their close relationship. According to Dr. Gill the
_Ammodytidæ_ belong near the _Hemerocœtidæ_.

[Illustration:

  FIG. 476.—Pearlfish, _Fierasfer dubius_ Putnam, embedded in a layer of
    mother-of-pearl. La Paz, Lower California. (Photograph by Capt. M.
    Castro.)
]

=The Pearlfishes: Fierasferidæ.=—In the little group of pearlfishes,
called _Fierasferidæ_ or _Carapidæ_, the body is eel-shaped with a
rather large head, and the vent is at the throat. Numerous species of
_Fierasfer_ (_Carapus_) are found in the warm seas. These little fishes
enter the cavities of sea-cucumbers (Holothurians) and other animals
which offer shelter, being frequently taken from the pearl-oyster. In
the Museum of Comparative Zoology, according to Professor Putnam, is
"one valve of a pearl-oyster in which a specimen of _Fierasfer dubius_
is beautifully inclosed in a pearly covering deposited on it by the
oyster." A photograph of a similar specimen is given above. The species
found in Holothurians are transparent in texture, with a bright pearly
luster. Species living among lava rocks, as _Jordanicus umbratilis_ of
the south seas, are mottled black. Since this was written a specimen of
this black species has been obtained from a Holothurian in Hilo, Hawaii,
by Mr. H. W. Henshaw.

[Illustration:

  FIG. 477.—Pearlfish, _Fierasfer acus_ (Linnæus), issuing from a
    Holothurian. Coast of Italy. (After Emery.)
]

=The Brotulidæ.=—The _Brotulidæ_ constitute a large family of fishes,
resembling codfishes, but differing in the character of the
hypercoracoid, as well as in the form of the tail. The resemblance
between the two groups is largely superficial. We may look upon the
_Brotulidæ_ as degraded blennies, but the _Gadidæ_ have an earlier and
different origin which has not yet been clearly made out. Most of the
_Brotulidæ_ live in deep water and are without common name or economic
relations. Two species have been landlocked in cave streams in Cuba,
where they have, like other cavefishes, lost their sight, a phenomenon
which richly deserves careful study, and which has been recently
investigated by Dr. C. H. Eigenmann. These blind Brotulids, called Pez
Ciego in Cuba, are found in different caves in the county of San
Antonio, where they reach a length of about five inches. As in other
blindfishes, the body is translucent and colorless. These species are
known as _Lucifuga subterranea_ and _Stygicola dentata_. They are
descended from allies of the genera called _Brotula_ and
_Dinematichthys_. _Brotula barbata_ is a cusk-like fish, occasionally
found in the markets of Havana. Similar species, _Brotula multibarbata_
and _Sirembo inermis_, are common in Japan, and _Brosmophycis
marginatus_, beautifully red in color, is occasionally seen on the coast
of California. Many other genera and species abound in the depths of the
sea and in crevices of coral reefs, showing much variety in form and
structure.

[Illustration:

  FIG. 478.—_Brotula barbata_ Schneider. Cuba.
]

[Illustration:

  FIG. 479.—Blind Brotula. _Lucifuga subterranea_ (Poey), showing
    viviparous habit. Joignan Cave, Pinar del Rio, Cuba. (Photograph by
    Dr. Eigenmann.)
]

The _Bregmacerotidæ_ are small fishes, closely related to the Brotulids,
having the hypercoracoid perforate, but with several minor
peculiarities, the first ray of the dorsal being free and much elongate.
They live near the surface in the open sea. _Bregmaceros macclellandi_
is widely diffused in the Pacific.

=Ateleopodidæ.=—The small family of _Ateleopodidæ_ includes long-bodied,
deep-water fishes of the Pacific, resembling _Macrourus_, but with
smooth scales. The group has the coracoids as in _Brotulidæ_, and the
actinosts are united in an undivided plate. _Ateleopus japonicus_ is the
species taken in Japan.

=Suborder Haplodoci.=—We may here place the peculiar family of
_Batrachoididæ_, or toadfishes. It constitutes the suborder of
_Haplodoci_ (ἁπλόος, simple; δόκος, shaft) from the simple form of the
post-temporal. This order is characterized by the undivided
post-temporal bone and by the reduction of the gill-arches to three. A
second bone behind the post-temporal connects the shoulder-girdle above
to the vertebral column. The coracoid bones are more or less elongate,
suggesting the arm seen in pediculate fishes.

The single family has the general form of the _Cottidæ_, the body
robust, with large head, large mouth, strong teeth, and short spinous
dorsal fin. The shoulder-girdle and its structures differ little from
the blennioid type. There are no pseudobranchiæ and the tail is
homocercal. The species are relatively few, chiefly confined to the warm
seas and mostly American, none being found in Europe or Asia. Some of
them ascend rivers, and all are carnivorous and voracious. None are
valued as food, being coarse-grained in flesh. The group is probably
nearest allied to the _Trachinidæ_ or _Uranoscopidæ_.

[Illustration:

  FIG. 480.—Leopard Toadfish, _Opsanus pardus_ (Goode & Bean).
    Pensacola.
]

_Opsanus tau_, the common toadfish, or oyster-fish, of our Atlantic
coast, is very common in rocky places, the young clinging to stones by a
sucking-disk on the belly, a structure which is early lost. It reaches a
length of about fifteen inches. _Opsanus pardus_, the leopard toadfish,
or sapo, of the Gulf coast, lives in deeper water and is prettily marked
with dark-brown spots on a light yellowish ground.

In _Opsanus_ the body is naked and there is a large foramen, or mucous
pore, in the axil of the pectoral. In the _Marcgravia cryptocentra_, a
large Brazilian toadfish, this foramen is absent. In _Batrachoides_, a
South American genus, the body is covered with cycloid scales.
_Batrachoides surinamensis_ is a common species of the West Indies.
_Batrachoides pacifici_ occurs at Panama. The genus _Porichthys_ is
remarkable for the development of series of mucous pores and luminous
spots in several different lateral lines which cover the body. These
luminous spots are quite unlike those found in the lantern-fishes
(_Myctophidæ_) and other _Iniomi_. Their structure has been worked out
in detail by Dr. Charles Wilson Greene, a summary of whose conclusions
are given on page 191, Vol. I.

The common midshipman, or singing fish, of the coast of California is
_Porichthys notatus_. This species, named midshipman from its rows of
shining spots like brass buttons, is found among rocks and kelp and
makes a peculiar quivering or humming noise with its large air-bladder.

_Porichthys porosissimus_, the bagre sapo, is common on all coasts of
the Gulf of Mexico and the Caribbean Sea. _Porichthys margaritatus_ is
found about Panama and _Porichthys porosus_ in Chile.

[Illustration:

  FIG. 481.—Singing Fish or Bagre Sapo, _Porichthys porosissimus_ (Cuv.
    & Val.). Galveston.
]

The species of _Thalassophryne_ and _Thalassothia_, the poison
toadfishes, are found along the coasts of South America, where they
sometimes ascend the rivers. In these species there is an elaborate
series of venom glands connected with the hollow spines of the opercle
and the dorsal spines. Dr. Günther gives the following account of this
structure as shown in _Thalassophryne reticulata_, a species from
Panama:

"In this species I first observed and closely examined the poison organ
with which the fishes of this genus are provided. Its structure is as
follows: (1) The opercular part: The operculum is very narrow,
vertically styliform and very mobile; it is armed behind with a spine,
eight lines long in a specimen of 10½ inches, and of the same form as
the venom fang of a snake; it is, however, somewhat less curved, being
only slightly bent upward. It has a longish slit at the outer side of
its extremity which leads into a canal perfectly closed and running
along the whole length of its interior; a bristle introduced into the
canal reappears through another opening at the base of the spine,
entering into a sac situated on the opercle and along the basal half of
the spine; the sac is of an oblong-ovate shape and about double the size
of an oat grain. Though the specimen had been preserved in spirits for
about nine months it still contained a whitish substance of the
consistency of thick cream, which on the slightest pressure freely
flowed from the opening in the extremity of the spine. On the other
hand, the sac could be easily filled with air or fluid from the foramen
of the spine. No gland could be discovered in the immediate neighborhood
of the sac; but on a more careful inspection I found a minute tube
floating free in the sac, whilst on the left-hand side there is only a
small opening instead of the tube. The attempts to introduce a bristle
into this opening for any distance failed, as it appears to lead into
the interior of the basal portion of the operculum, to which the sac
firmly adheres at this spot. (2) The dorsal part is composed of the two
dorsal spines, each of which is ten lines long. The whole arrangement is
the same as in the opercular spines; their slit is at the front side of
the point; each has a separate sac, which occupies the front of the
basal portion; the contents were the same as in the opercular sacs, but
in somewhat greater quantity. A strong branch of the lateral line
ascends to the immediate neighborhood of their base. Thus we have four
poison spines, each with a sac at its base; the walls of the sacs are
thin, composed of a fibrous membrane, the interior of which is coated
over with mucus. There are no secretory glands embedded between these
membranes, and these sacs are probably merely the reservoirs in which
the fluid secreted accumulates. The absence of a secretory organ in the
immediate neighborhood of the reservoirs (an organ the size of which
would be in accordance with the quantity of fluid secreted), the
diversity of the osseous spines which have been modified into poison
organs, and the actual communication indicated by the foramen in the sac
lead me to the opinion that the organ of secretion is either that system
of muciferous channels which is found in nearly the whole class of
fishes, and the secretion of which has poisonous qualities in a few of
them, or at least an independent portion of it. This description was
made from the first example; through the kindness of Captain Dow I
received two other specimens, and in the hope of proving the connection
of the poison bags with the lateral-line system, I asked Dr. Pettigrew,
of the Royal College of Surgeons, a gentleman whose great skill has
enriched that collection with a series of the most admirable anatomical
preparations, to lend me his assistance in injecting the canals. The
injection of the bags through the opening of the spine was easily
accomplished; but we failed to drive the fluid beyond the bag or to fill
with it any other part of the system of muciferous channels. This,
however, does not disprove the connection of the poison bags with that
system, inasmuch as it became apparent that if there be minute openings
they are so contracted by the action of the spirit in which the
specimens were preserved as to be impassable to the fluid of injection.
A great part of the lateral-line system consists of open canals;
however, on some parts of the body, these canals are entirely covered by
the skin; thus, for instance, the open lateral line ceases apparently in
the suprascapular region, being continued in the parietal region. We
could not discover any trace of an opening by which the open canal leads
to below the skin; yet we could distinctly trace the existence of the
continuation of the canal by a depressed line, so that it is quite
evident that such openings do exist, although they may be passable only
in fresh specimens. Thus likewise the existence of openings in the bags,
as I believed to have found in the first specimen dissected, may be
proved by examination of fresh examples. The sacs are without an
external muscular layer and situated immediately below the loose thick
skin which envelops their spines to their extremity. The injection of
the poison into a living animal, therefore, can only be effected by the
pressure to which the sac is subjected the moment the spine enters
another body. Nobody will suppose that a complicated apparatus like the
one described can be intended for conveying an innocuous substance, and
therefore I have not hesitated to designate it as poisonous; and,
Captain Dow informs me in a letter lately received, 'the natives of
Panama seemed quite familiar with the existence of the spines and of the
emission from them of a poison which, when introduced into a wound,
caused fever, an effect somewhat similar to that produced by the sting
of a scorpion; but in no case was a wound caused by one of them known to
result seriously. The slightest pressure of the finger at the base of
the spine caused the poison to jet a foot or more from the opening of
the spine.' The greatest importance must be attached to this fact,
inasmuch as it assists us in our inquiries into the nature of the
functions of the muciferous system, the idea of its being a secretory
organ having lately been superseded by the notion that it serves merely
as a stratum for the distribution of peripheric nerves. Also the
objection that the sting-rays and many Siluroid fishes are not poisonous
because they have no poison organ cannot be maintained, although the
organs conveying their poison are neither so well adapted for this
purpose nor in such a perfect connection with the secretory mucous
system as in _Thalassophryne_. The poison organ serves merely as a
weapon of defense. All the Batrachoids with obtuse teeth on the palate
and in the lower jaw feed on Mollusca and Crustaceans."

No fossil _Batrachoididæ_ are known.

=Suborder Xenopterygii.=—The clingfishes, forming the suborder
_Xenopterygii_ (ξενός, strange; πτερύξ, fin), are, perhaps, allied to
the toadfishes. The ventral fins are jugular, the rays I, 4 or I, 5, and
between them is developed an elaborate sucking-disk, not derived from
modified fins, but from folds of the skin and underlying muscles.

The structure of this disk in _Gobiesox sanguineus_ is thus described by
Dr. Günther:

"The whole disk is exceedingly large, subcircular, longer than broad,
its length being (often) one-third of the whole length of the fish. The
central portion is formed merely by skin, which is separated from the
pelvic or pubic bones by several layers of muscles. The peripheric
portion is divided into an anterior and posterior part by a deep notch
behind the ventrals. The anterior peripheric portion is formed by the
ventral rays, the membrane between them and a broad fringe which extends
anteriorly from one ventral to the other. This fringe is a fold of the
skin, containing on one side the rudimentary ventral spine, but no
cartilage. The posterior peripheric portion is suspended on each side on
the coracoid, the upper bone of which is exceedingly broad, becoming a
free, movable plate behind the pectoral. The lower bone of the coracoid
is of a triangular form, and supports a very broad fold of the skin,
extending from one side to the other, and containing a cartilage which
runs through the whole of that fold. Fine processes of the cartilage are
continued into the soft striated margin, in which the disk terminates
posteriorly. The face of the disk is coated with a thick epidermis, like
the sole of the foot in higher animals. The epidermis is divided into
many polygonal plates. There are no such plates between the roots of the
ventral fins."

[Illustration:

  FIG. 482.—_Aspasma ciconiæ_ Jordan & Snyder. Wakanoura, Japan.
]

The body is formed much as in the toadfishes. The skin is naked and
there is no spinous dorsal fin. The skeleton shows several
peculiarities; there is no suborbital ring, the palatine arcade is
reduced, as are the gill-arches, the opercle is reduced to a spine-like
projection, and the vertebræ are numerous. The species are found in
tide-pools in the warm seas, where they cling tightly to the rocks with
their large ventral disks.

Several species of _Lepadogaster_ and _Mirbelia_ are found in the
Mediterranean. _Lepadogaster gouani_ is the best-known European species.
_Aspasma ciconiæ_ and _minima_ occur about the rocks in the bays of
Japan.

[Illustration:

  FIG. 483.—Clingfish, _Caularchus mæandricus_ (Girard). Monterey, Cal.
]

Most of the West Indian species belong to _Gobiesox_, with entire teeth,
and to _Arbaciosa_, with serrated teeth. Some of these species are deep
crimson in color, but most of them are dull olive. _Gobiesox virgatulus_
is common on the Gulf Coast. _Caularchus mæandricus_, a very large
species, reaching a length of six inches, abounds along the coast of
California. Other genera are found at the Cape of Good Hope, especially
about New Zealand. _Chorisochismus dentex_, from the Cape of Good Hope,
reaches the length of a foot.



                              CHAPTER XXX
                       OPISTHOMI AND ANACANTHINI


=ORDER Opisthomi.=—The order _Opisthomi_ (ὄπισθη, behind; ὤμος,
shoulder) is characterized by the general traits of the blennies and
other elongate, spiny-rayed fishes, but the shoulder-girdle, as in the
Apodes and the _Heteromi_, is inserted on the vertebral column well
behind the skull.

The single family, _Mastacembelidæ_, is composed of eel-shaped fishes
with a large mouth and projecting lower jaw, inhabiting the waters of
India, Africa, and the East Indies. They are small in size and of no
economic importance. The dorsal is long, with free spines in front and
there are no ventral fins. Were these fins developed, they should in
theory be jugular in position. There is no air-duct in _Mastacembelus_
and it seems to be a true spiny-rayed fish, having no special relation
to either _Notacanthus_ or to the eels. Except for the separation of the
shoulder-girdle from the skull, there seems to be no reason for
separating them far from the Blennioid forms, and the resemblance to
_Notacanthus_ seems wholly fallacious.

[Illustration:

  FIG. 484.—_Mastacembelus ellipsifer_ Boulenger. Congo River. (After
    Boulenger.)
]

_Mastacembelus armatus_ is a common species of India and China. In
_Rhynchobdella_ the nasal appendage or proboscis, conspicuous in
_Mastacembelus_, is still more developed. _Rhynchobdella aculeata_ is
common in India.

=Order Anacanthini.=—We may separate from the other jugular fishes the
great group of codfishes and their allies, retaining the name
Anacanthini (ἄνακανθος, without spine) suggested by Johannes Müller. In
this group the hypercoracoid is without foramen, the fenestra lying
between this bone and the hypocoracoid below it. The tail is isocercal,
the vertebræ in a right line and progressively smaller backward,
sometimes degenerate or whip-like (leptocercal) at tip. Other characters
are shown in the structure of the skull. There are no spines in any of
the fins; the ventrals are jugular, the scales generally small, and the
coloration dull or brownish. The numerous species live chiefly in the
northern seas, some of them descending to great depths. The resemblance
of these fishes to some of the Blennioid group is very strongly marked,
but these likenesses seem analogical only and not indicative of true
affinity. The codfishes probably represent an early offshoot from the
ancestors of the spiny-rayed fishes, and their line of evolution is
unknown, possibly from Ganoid types. Among recent fishes there is
nothing structurally nearer than the _Nototheniidæ_ and _Brotulidæ_, but
the line of descent must branch off much farther back than either of
these. For the present, therefore, we may regard the codfishes and their
allies (_Anacanthini_) as a distinct order.

[Illustration:

  FIG. 485.—Codfish, _Gadus callarias_ L. Eastport, Me.
]

=The Codfishes: Gadidæ.=—The chief family is that of the _Gadidæ_, or
codfishes. These are characterized by a general resemblance to the
common codfish, _Gadus callarias_. This is one of the best known of
fishes, found everywhere on the shores of the North Atlantic, and the
subject of economic fisheries of the greatest importance. Its flesh is
white, flaky, rather tasteless, but takes salt readily, and is
peculiarly well adapted for drying. The average size of the codfish is
about ten pounds, but Captain Nathaniel Atwood of Provincetown records
one with the weight of 160 pounds.

According to Dr. Goode:

"In the western Atlantic the species occurs in the winter in
considerable abundance as far south as the mouth of the Chesapeake Bay,
latitude 37°, and stragglers have been observed about Ocracoke Inlet.
The southern limits of the species may be safely considered to be Cape
Hatteras, in latitude 35° 10´. Along the coast of New England, the
Middle States, and British North America, and upon all the off-shore
banks of this region, cod are found usually in great abundance, during
part of the year at least. They have been observed also in the Gulf of
Bothnia, latitude 70° to 75°, and in the southeastern part of Baffin's
Land to the northward of Cumberland Sound, and it is more than probable
that they occur in the waters of the Arctic Sea to the north of the
American continent, or away around to Bering Strait."

Dr. Gill says:

"The ocean banks of moderate depths are the favorite resorts of the cod,
but it is by no means confined to those localities. The fish, indeed,
occasionally enters into fresh, or at least brackish, water. According
to Canadian authorities, it is found 'well up the estuary of the St.
Lawrence, though how far up is not definitely stated, probably not
beyond the limits of brackish water.' Even as far south as the Delaware
River it has been known to enter the streams. Dr. C. C. Abbott records
that in January, 1876, 'a healthy, strong, active codfish, weighing
nearly four pounds, was taken in a draw-net in the Delaware River near
Trenton, New Jersey; the stomach of the fish showed that it had been in
river-water several days. Many of them had been taken about Philadelphia
between 1856 and 1869.'

"The cod ranks among the most voracious of ordinary fishes, and almost
everything that is eatable, and some that is not, may find its way into
its capacious maw. Years ago, before naturalists had the facilities that
the dredge now affords, cods' stomachs were the favorite resort for rare
shells, and some species had never been obtained otherwise than through
such a medium, while many filled the cabinet that would not otherwise
have been represented. In the words of Mr. Goode, 'codfish swallow
bivalve fish of the largest size, like the great sea-clams, which are a
favorite article of food on certain portions of the coast'; further,
'these shells are nested, the smaller inside of the larger, sometimes
six or seven in a set, having been packed together in this compact
manner in the stomachs of the codfish after the soft parts have been
digested out. Some of them had shreds of the muscles remaining in them
and were quite fresh, having evidently been but recently ejected by the
fish.' Even banks of dead shells have been found in various regions,
which are supposed to be the remains of mollusks taken by the cod.
Shell-fishes, however, form probably but the smaller portion of its
diet, and fishes of its own class contribute materially to its food,—
such as the herring family, the capelin, etc.

"The codfish in its mode of reproduction exhibits some interesting
peculiarities. It does not come on the coast to spawn, as was once
supposed, but its eggs are deposited in mid-sea and float to the
surface, although it does really, in many cases, approach the land to do
so. Prof. C. O. Sars, who has discovered its peculiarities, 'found cod
at a distance of twenty to thirty Norwegian miles from the shore and at
a depth of from one hundred to one hundred and fifty fathoms.' The eggs
thus confided to the mercy of the waves are very numerous; as many as
9,100,000 have been calculated in a seventy-five-pound fish. 'When the
eggs are first seen in the fish they are so small as to be hardly
distinguishable; but they continue to increase in size until maturity,
and after impregnation have a diameter depending upon the size of the
parent, varying from one-nineteenth to one-seventeenth of an inch. A
five- to eight-pound fish has eggs of the smaller size, while a
twenty-five-pound one has them between an eighteenth and a seventeenth.'
There are about 190,000 eggs of the smaller size to a pound avoirdupois.
They are matured and ejected from September to November."

Unlike most fishes, the cod spawns in cooling water, a trait also found
in the salmon family.

The liver of the cod yields an easily digested oil of great value in the
medical treatment of diseases causing emaciation.

The Alaska cod, _Gadus macrocephalus_, is equally abundant with the
Atlantic species, from which it differs very slightly, the air-bladder
or sounds being smaller, according to the fishermen, and the head being
somewhat larger. This species is found from Cape Flattery to Hakodate in
Japan, and is very abundant about the Aleutian Islands and especially in
the Okhotsk Sea. With equal markets it would be as important
commercially as the Atlantic cod. In the codfish (_Gadus_) and related
genera there are three dorsal and two anal fins. In the codfish the
lateral line is pale and the lower jaw shorter than the upper.

[Illustration:

  FIG. 486.—Skull of Haddock, _Melanogrammus æglifinus_.
]

[Illustration:

  FIG. 487.—Haddock, _Melanogrammus æglifinus_ (L.). Eastport, Me.
]

The haddock (_Melanogrammus æglifinus_) closely resembles the cod and is
of similar quality as food. It is known at sight by the black lateral
line. It is found on both shores of the Atlantic and when smoked is the
"finnan haddie" of commerce.

The pollack, coalfish, or green cod (_Pollachius carbonarius_) is also
common on both shores of the north Atlantic. It is darker than the cod
and more lustrous, and the lower jaw is longer, with a smaller barbel at
tip. It is especially excellent when fresh.

[Illustration:

  FIG. 488.—Pollock, _Theragra chalcogramma_ (Pallas). Shumagin I.,
    Alaska.
]

The whiting (_Merlangus merlangus_) is a pollack-like fish common on the
British coasts, but not reaching the American shores. It is found in
large schools in sandy bays. The Alaska pollack (_Theragra
chalcogramma_) is a large fish with projecting lower jaw, widely
diffused in the north Pacific and useful as a food-fish to the Aleutian
peoples. It furnishes a large part of the food of the fur-seal
(_Callorhinus alascanus_ and _C. ursinus_) during its migrations. The
fur-seal rarely catches the true codfish, which swims near the bottom.
The wall-eyed pollack (_Theragra fucensis_) is found about Puget Sound.
Smaller codfishes of this type are the wachna cod (_Eleginus navaga_) of
Siberia and the Arctic codling (_Boreogadus saida_), both common about
Kamchatka, the latter crossing to Greenland.

Several dwarf codfishes having, like the true cod, three dorsal fins and
a barbel at the chin are also recorded. Among these are the tomcod, or
frostfish, of the Atlantic (_Microgadus tomcod_), the California tomcod
(_Microgadus proximus_), and _Micromesistius poutassou_ of the
Mediterranean. These little cods are valued as pan fishes, but the flesh
is soft and without much flavor.

[Illustration:

  FIG. 489.—Tomcod, _Microgadus tomcod_ (Walbaum). Wood's Hole, Mass.
]

Other cod-like fishes have but two dorsals and one anal fin. Many of
these occur in deep water. Among those living near shore, and therefore
having economic value, we may mention a few of the more prominent. The
codlings (_Urophycis_) are represented by numerous species on both
shores of the Atlantic. _Urophycis blennoides_ is common in the
Mediterranean. _Urophycis regius_, on our South Atlantic coast, is said
to exhibit electric powers in life, a statement that needs verification.
In the Gulf of Mexico _Urophycis floridanus_ is common. Farther north
are the more important species _Urophycis tenuis_, called the white
hake, and _Urophycis chuss_, the squirrel-hake. The ling (_Molva molva_)
is found in deep water about the North Sea.

A related genus, _Lota_, the burbot, called also ling and, in America,
the lawyer, is found in fresh waters. This genus contains the only
fresh-water members of the group of _Anacanthini_.

The European burbot, _Lota lota_, is common in the streams and lakes of
northern Europe and Siberia. It is a bottom fish, coarse in flesh and
rather tasteless, eaten sometimes when boiled and soaked in vinegar or
made into salad. It is dark olive in color, thickly marbled with
blackish.

The American burbot, or lawyer (_Lota maculosa_), is very much like the
European species. It is found from New England throughout the Great
Lakes to the Yukon. It reaches a length of usually two or three feet and
is little valued as food in the United States, but rises much in esteem
farther north. The liver and roe are said to be delicious. In Siberia
its skin is used instead of glass for windows. In Alaska, according to
Dr. Dall, it reaches a length of six feet and a weight of sixty pounds.

[Illustration:

  FIG. 490.—Burbot, _Lota maculosa_ (Le Sueur). New York.
]

[Illustration:

  FIG. 491.—Four-bearded Rockling, _Enchelyopus cimbrius_ (Linnæus).
    Nahant, Mass.
]

The rocklings (_Gaidropsarus_ and _Enchelyopus_) have the first dorsal
composed of a band of fringes preceded by a single ray. The species are
small and slender, abounding chiefly in the Mediterranean and the North
Atlantic. The young have been called "mackerel-midges." Our commonest
species is _Enchelyopus cimbrius_, found also in Great Britain.

The cusk, or torsk, _Brosme brosme_, has a single dorsal fin only. It is
a large fish found on both shores of the North Atlantic, but rather rare
on our coasts.

Fossil codfishes are not numerous. Fragments thought to belong to this
family are found in English Eocene rocks.

_Nemopteryx troscheli_, from the Oligocene of Glarus, has three dorsal
fins and a lunate caudal fin. Other forms have been referred with more
or less doubt to _Gadus_, _Brosmius_, _Strinsia_, and _Melanogrammus_.

Gill separates the "three-forked hake" (_Raniceps trifurcus_) of
northern Europe as a distinct family, _Ranicipitidæ_. In this species
the head is very large, broad and depressed, differing in this regard
from the codlings and hakes, which have also two dorsal fins. The
deep-water genus, _Bathyonus_, is also regarded as a distinct family,
_Bathyonidæ_.

=The Hakes: Merluciidæ.=—Better defined than these families is the
family of hakes, _Merluciidæ_. These pike-like codfishes have the skull
peculiarly formed, the frontal bones being paired, excavated above, with
diverging crests continuous forward from the forked occipital crest. The
species are large fishes, very voracious, without barbels, with the
skeleton papery and the flesh generally soft. The various species are
all very much alike, large, ill-favored fishes with strong teeth and a
ragged appearance, the flesh of fair quality. _Merluccius merluccius_,
the hake or stock-fish, is common in Europe; _Merluccius bilinearis_,
the silver hake, is common in New England, _Merluccius productus_ in
California, and _Merluccius gayi_ in Chile.

[Illustration:

  FIG. 492.—California Hake, _Merluccius productus_ (Ayres). Seattle.
]

[Illustration:

  FIG. 493.—_Coryphænoides carapinus_ (Goode & Bean), showing leptoceral
    tail. Gulf Stream.
]

=The Grenadiers: Macrouridæ.=—The large family of grenadiers, or
rat-tails, _Macrouridæ_, is confined entirely to the oceanic depths,
especially of the north Atlantic and Pacific. The head is formed much as
in the codfishes, with usually a barbel at the chin. There are two
dorsals, the second like the anal being low, but the leptocercal tail is
very long and tapering, ending in a filament without caudal fin. The
scales are usually rough and spinous. The species are usually large in
size, and dull gray or black in color.

[Illustration:

  FIG. 494.—Grenadier, _Cœlorhynchus carminatus_ Goode & Bean. Martha's
    Vineyard.
]

The best-known genus is _Macrourus_. _Macrourus berglax_ is found on
both shores of the north Atlantic. _Macrourus bairdi_ is abundant in
off-shore dredgings from Cape Cod to Cuba. _Macrourus cinereus_, the
pop-eye grenadier, outnumbers all other fishes in the depths of Bering
Sea. _Cœlorhynchus japonicus_ is often taken by fishermen in Japan.
_Coryphænoides rupestris_ is common in the north Atlantic. _Bogoslovius
clarki_ and _Albatrossia pectoralis_ were dredged by the _Albatross_
about the volcanic island of Bogoslof. _Trachyrhynchus trachyrhynchus_
is characteristic of the Mediterranean. _Nematonurus goodei_ is common
in the Gulf Stream, and _Dolloa longifilis_ is found off Japan. Other
prominent genera are _Bathygadus_, _Gadomus_, _Regania_, and
_Steindachnerella_.

[Illustration:

  FIG. 495.—_Steindachnerella argentea_ (Goode & Bean). Gulf Stream.
]

The _Murænolepidæ_ are deep-sea fishes, with minute eel-like scales, and
no caudal fin. The ventrals are five-rayed and there are 10 pterygials.



                              CHAPTER XXXI
                     ORDER PEDICULATI: THE ANGLERS


=THE Angler-fishes.=—The few remaining fishes possess also jugular
ventral fins, but in other regards they show so many peculiarities of
structure that we may well consider them as forming a distinct order,
_Pediculati_ (_pedicula_, a foot-stalk), although the relation of these
forms to the _Batrachoididæ_ seems a very close one.

The most salient character of the group is the reduction and backward
insertion of the gill-opening, which is behind the pectoral fins, not in
front of them as in all other fishes. The hypocoracoid and hypercoracoid
are much elongate and greatly changed in form, so that the pectoral fin
is borne on the end of a sort of arm. The large ventrals are similarly
more or less exserted. The spinous dorsal is much reduced, the first
spine being modified to form a so-called fishing-rod, projecting over
the mouth with a fleshy pad, lure, or bait at its tip. The form of the
body varies much in the different families. The scales are lost or
changed to prickles and the whole aspect is very singular, and in many
cases distinctly frog-like. The species are mostly tropical, some living
in tide-pools and about coral reefs, some on sandy shores, others in the
oceanic abysses.

The nearest allies of the Pediculates among normal fishes are probably
the _Batrachoididæ_. One species of _Lophiidæ_ is recorded among the
fossils, _Lophius brachysomus_, from the Eocene of Monte Bolca. No
fossil _Antennariidæ_ are known. Fossil teeth from the Cretaceous of
Patagonia are doubtfully named "_Lophius patagonicus_."

=The Fishing-frogs: Lophiidæ.=—In the most generalized family, that of
the fishing-frogs (_Lophiidæ_), the body is very much depressed, the
head the largest part of it. The mouth is excessively wide, with strong
jaw-muscles, and strong sharp teeth. The skin is smooth, with dermal
flaps about the head. Over the mouth, like a fishing-rod, hangs the
first dorsal spine with a lure at the tip. The fishes lie flat on the
bottom with sluggish movements except for the convulsive snap of the
jaws. It has been denied that the bait serves to attract small fishes to
their destruction, but the current belief that it does so is certainly
plausible. As to this Dr. Gill observes:

"The name 'angler' is derived from the supposition that by means of the
foremost dorsal spine, which bears leaf-like tags, or appendages, at the
end, it angles for fishes itself, lying upon the ground with its head
somewhat upraised. According to Mr. S. Kent, however, this is at most
only partly the case: 'That the fish deliberately uses this structure as
a fisherman does his rod and line for the alluring and capture of other
fish is a matter of tradition handed down to us from the time of Pliny
and Aristotle, and which scarcely any authority since their time has
ventured to gainsay. Nevertheless, like many of the delightful
natural-history romances bequeathed to us by the ancient philosophers,
this one of the angler-fish will have to be relegated to the limbo of
disproved fiction. The plain and certain ground of facts, all the same,
has frequently more startling revelations in store for us than the most
fervid imaginations of philosophers, and that this assertion holds good
in the case now under consideration must undoubtedly be admitted. It is
here proposed to show, in fact, that the angler is one of the most
interesting examples upon which Nature has exercised her handicraft, in
the direction of concealing the identity of her protégé, such ingenuity
being sometimes utilized with the object of protecting the organism from
the attacks of other animals, or, as illustrated in the present
instance, for the purpose of enabling it by stealth to obtain prey which
it lacks the agility to hunt down after the manner of ordinary
carnivorous fishes. To recognize the several details here described, it
will not suffice to refer to examples simply, and usually most
atrociously stuffed, nor even to those preserved in spirit, in which all
the life colors are more or less completely obliterated and the various
membranous appendages shrunk up and distorted. In place of this, a
healthy, living example fresh from the sea, or, better still,
acclimatized in the tanks of an aquarium, must be attentively examined,
and whereupon it will be found that this singular fish, throughout the
whole extent of its superficies, may be appropriately designated a
living sham."

It was, in the first place, observed by Mr. Kent "that the fish while
quietly reclining upon the bottom of its tank presented a most
astonishing resemblance to a piece of inert rock, the rugose prominences
in the neighborhood of the head lending additional strength to this
likeness. This resemblance being recognized, it was next found, on a
little closer inspection, that the fish constituted, in connection with
its color, ornamentations, and manifold organs and appendages, the most
perfect facsimile of a submerged rock, with that natural clothing of
sedentary animal and vegetable growths common to boulders lying beneath
the water in what is known as the laminarian zone. In this manner the
numerous simple or lobulated membranous structures dependent from the
lower jaw and developed as a fringe along the lateral line of the body
imitate with great fidelity the little flat calcareous sponges
(_Grantia_), small compound ascidians, and other low organized zoophytic
growths that hang in profusion from favorably situated submarine stones.
That famous structure known as the angler's 'rod and bait' finds its
precise counterpart in the early growing phase of certain sea-plants,
such as the oarweed (_Laminaria_), while the more posterior dorsal
fin-rays, having short lateral branchlets, counterfeit in a like manner
the plant-like hydroid zoophytes known as _Sertulariæ_. One of the most
extraordinary mimetic adaptations was, however, found in connection with
the eyes, structures which, however perfectly the surrounding details
may be concealed, serve, as a rule, to betray the animal's presence to a
close observer. In the case of the angler, the eyes during life are
raised on conical elevations the sides of which are separated by darker
longitudinal stripes into symmetrical regions, the structure, as a
whole, with its truncated summit upon which the pupil opens, reproducing
with the most wonderful minuteness the multivalve shell of a rook
barnacle (_Balanus_). To complete the simile the entire exposed surface
of the body of the fish is mapped out by darker punctated lines into
irregular polygonal areas, whose pattern is at once recognized by the
student of marine zoology as corresponding with that of the flat,
cushion-like expansions of the compound tunicate _Botryllus violaceus_.
Thus disguised at every point, the angler has merely to lie prone, as is
its wont, among the stones and débris at the bottom of the sea and to
wait for the advent of its unsuspecting prey, which, approaching to
browse from what it takes to be a flat rock—differing in no respect from
that off which it obtained the last appetizing morsel of weed or worm—
finds itself suddenly engulfed beyond recall within the merciless jaws
of this marine impostor."

[Illustration:

  FIG. 496.—Anko or Fishing-frog, _Lophius litulon_ (Jordan). Matsushima
    Bay, Japan.
]

The great fishing-frog of the North Atlantic, _Lophius piscatorius_, is
also known as angler, monkfish, goosefish, allmouth, wide-gape,
kettleman, and bellows-fish. It is common in shallow water both in
America and Europe, ranging southward to Cape Hatteras and to the
Mediterranean. It reaches a length of three feet or more. A fisherman
told Mr. Goode that "he once saw a struggle in the water, and found that
a goosefish had swallowed the head and neck of a large loon, which had
pulled it to the surface and was trying to escape. There is authentic
record of seven wild ducks having been taken from the stomach of one of
them. Slyly approaching from below, they seize birds as they float upon
the surface."

"The angler, or goosefish, spawns in summer along the eastern Atlantic
coast, and the result of its labor is quite remarkable. 'The eggs are
very numerous, inclosed in a ribbon-shaped gelatinous mass, about a foot
in width and thirty or forty feet long, which floats near the surface.
One of these ribbons will weigh perhaps forty pounds, and is usually
partially folded together and visible a foot or eighteen inches from the
top of the water, its color being brownish purple. The number of eggs in
one of these has been estimated to be from forty to fifty thousand.' The
growth of the young after exclusion from the egg is rather rapid, and
Professor Goode saw 'young fish two or three inches long' while others
were yet spawning, and these young fish were presumably the fry of those
that had spawned the same year, only somewhat earlier. In a few days
after hatching they present a striking appearance on account of the
enormous development of the pectoral and ventral fins."

Aristotle gives, according to Professor Horace A. Hoffman, this account
of the angler: "'Inasmuch as the flat, front part is not fleshy, nature
has compensated for this by adding to the rear and the tail as much
fleshy substance as has been subtracted from the front.' The βάτραχος is
called the angler. He fishes with the hair-like filaments hung before
his eyes. On the end of each filament is a little knob, just as if it
had been placed there for a bait. He makes a disturbance in sandy or
muddy places, hides himself and raises these filaments. When the little
fish strikes at them he leads them down with the filaments until he
brings them to his mouth. The βάτραχος is one of the σελάχη. All the
σελάχη are viviparous or ovoviviparous except the βάτραχος. The other
flat σελάχη have their gills uncovered and underneath them, but the
βάτραχος has its gills on the side and covered with skinny opercula, not
with horny opercula like the fish which are not σελαχώδη. Some fishes
have the gall-bladder upon the liver, others have it upon the intestine,
more or less remote from the liver and attached to it by a duct. Such
are βάτραχος, ἔλλοψ, συνάγρίς, σμύραινα, and ξιφίας. The βάτραχος is the
only one of the σελάχη which is oviparous. This is on account of the
nature of its body, for it has a head many times as large as the rest of
its body, and spiny and very rough. For this same reason it does not
afterwards admit its young into itself. The size and roughness of the
head prevent them both from coming out (i.e., being born alive) and from
going in (being taken into the mouth of the parent). The βάτραχος is the
most prolific of the σελάχη, but it is scarce because the eggs are
easily destroyed, for it lays them in a bunch near the shore."

The genus _Lophius_ of northern range has a vertebral column of about
thirty vertebræ. _Lophius litulon_ occurs in Japan. In the North Pacific
is found _Lophiomus_, similar in appearance but smaller in size, ranging
southward to the equator, a southern fish having but eighteen vertebræ.
_Lophiomus setigerus_ is the common anko of Japan, and other species are
recorded from Hawaii, and the Galapagos.

=The Sea-devils: Ceratiidæ.=—The sea-devils, or _Ceratiidæ_, are
degenerate anglers of various forms, found in the depths of the arctic
seas. The body is compressed, the mouth vertical; the substance is very
soft, and the color uniform black. Dr. Günther thus speaks of them:

[Illustration:

  FIG. 497.—_Cryptopsaras couesi_ Gill. Gulf Stream.
]

[Illustration:

  FIG. 498.—Deep-sea Angler, _Ceratias holbolli_ Kröyer. Greenland.
]

[Illustration:

  FIG. 499.—_Caulophryne jordani_ Goode & Bean. Gulf Stream. Family
    _Ceratiidæ_.
]

"The bathybial sea-devils are degraded forms of _Lophius_; they descend
to the greatest depths of the ocean. Their bones are of an extremely
light and thin texture, and frequently other parts of their
organization, their integuments, muscles, and intestines are equally
loose in texture when the specimens are brought to the surface. In their
habits they probably do not differ in any degree from their surface
representative, _Lophius_. The number of the dorsal spines is always
reduced, and at the end of the series of these species only one spine
remains, with a simple, very small lamella at the extremity
(_Melanocetus johnsonii_, _Melanocetus murrayi_). In other forms
sometimes a second cephalic spine, sometimes a spine on the back of the
trunk, is preserved. The first cephalic spine always retains the
original function of a lure for other marine creatures, but to render it
more effective a special luminous organ is sometimes developed in
connection with the filaments with which its extremity is provided
(_Ceratias bispinosus_, _Oneirodes eschrichtii_). So far as known at
present these complicated tentacles attain to the highest degree of
development in _Himantolophus_ and _Ægæonichthys_. In other species very
peculiar dermal appendages are developed, either accompanying the spine
on the back or replacing it. They may be paired or form a group of
three, are pear-shaped, covered with common skin, and perforated at the
top, a delicate tentacle sometimes issuing from the foramen."

Of the fifteen or twenty species of _Ceratiidæ_ described, none are
common and all are rare catches of the deep-sea dredge. _Caulophryne
jordani_ is remarkable for its large fins and the luminous filaments,
_Linophryne lucifer_ for its large head, and _Corynolophus reinhardti_
(Fig. 143, Vol. I) for its luminous fishing-bulb.

[Illustration:

  FIG. 500.—Sargassum-fish, _Pterophryne tumida_ (Osbeck). Florida.
    Family _Antennariidæ_.
]

=The Frogfishes: Antennariidæ.=—The frogfishes, _Antennariidæ_, belong
to the tropical seas and rarely descend far below the surface. Most of
them abound about sand-banks or coral reefs, especially along the shores
of the East and West Indies, where they creep along the rocks like
toads. Some are pelagic, drifting about in floating masses of seaweed.
All are fantastic in form and color, usually closely imitating the
objects about them. The body is compressed, the mouth nearly vertical,
and the skin either prickly or provided with fleshy slips.

The species of _Pterophryne_ live in the open sea, drifting with the
currents in masses of sargassum. Two species, _Pterophryne tumida_ and
_Pterophryne gibba_, are found in the West Indies and Gulf Stream. Two
others very similar, _Pterophryne histrio_ and _Pterophryne ranina_,
live in the East Indies and drift in the Kuro Shiwo of Japan. All these
are light olive-brown with fantastic black markings.

[Illustration:

  FIG. 501.—Fishing-frog, _Antennarius nox_ Jordan. Wakanoura, Japan.
]

The genus _Antennarius_ contains species of the shoals and reefs, with
markings which correspond to the colors of the rocks. These fishes are
firm in texture with a velvety skin, and the prevailing color is brown
and red. There are many species wherever reefs are found. _Antennarius
ocellatus_, the pescador, is the commonest West Indian species.
_Antennarius multiocellatus_, with many ocellated spots, is the Martin
Pescador of Cuba, also common.

On the Pacific coast of Mexico the commonest species is _Antennarius
strigatus_. In Japan, _Antennarius tridens_ abounds everywhere on the
muddy bottoms of the bays. _Antennarius_ _nox_ is a jet-black species of
the Japanese reefs, and _Antennarius sanguifluus_ is spotted with
blood-red in imitation of coralline patches. Many other species abound
in the East Indies and in Polynesia. The genus _Chaunax_ is represented
by several deep-water species of the West Indies, Japan, etc.

[Illustration:

  FIG. 502.—Shoulder-girdle of a Batfish, _Ogcocephalus radiatus_
    (Mitchill).
]

The _Gigactinidæ_ of the deep seas differ from the _Ogcocephalidæ_,
according to Boulenger, in the absence of ventrals.

[Illustration:

  FIG. 503.—Frogfish, _Antennarus scaber_ (Cuvier). Puerto Rico.
]

=The Batfishes: Ogcocephalidæ.=—The batfishes, _Ogcocephalidæ_, are
anglers with the body depressed and covered with hard bony warts. The
mouth is small and the bony bases of the pectoral and ventral fins are
longer than in any other of the anglers. The species live in the warm
seas, some in very shallow water, others descending to great depths, the
deep-sea forms being small and more or less degenerate. These walk along
like toads on the sea-bottoms; the ventrals, being jugular, act as fore
legs and the pectorals extend behind them as hind legs.

[Illustration:

  FIG. 504.—_Ogcocephalus vespertilio_ (L.). Florida.
]

The common sea-bat, or diablo, of the West Indies, _Ogcocephalus
vespertilio_, is dusky in color with the belly coppery red. It reaches
the length of a foot. The angling spine is very short, hidden under the
long stiff process of the snout. Farther north occurs the short-nosed
batfish, _Ogcocephalus radiatus_, very similar, but with the nostril
process, or snout, blunt and short. _Zalieutes elater_, with a large
black eye-like spot on each side of the back, is found on the west coast
of Mexico. In deeper water are species of _Halieutichthys_ in the West
Indies and of _Halieutæa_ in Japan. _Dibranchus atlanticus_ has the
gills reduced to two pairs. _Malthopsis_ consists of small species, with
the rostrum prominent, like a bishop's miter. Two species are found in
the Pacific, _Malthopsis mitrata_ in Hawaii and _Malthopsis tiarella_ in
Japan.

                  *       *       *       *       *

And with these dainty freaks of the sea, the results of centuries on
centuries of specialization, degeneration, and adaptation, we close the
long roll-call of the fishes, living and dead. And in their long
genealogy is enfolded the genealogy of men and beasts and birds and
reptiles and of all other back-boned animals of whom the fish-like forms
are at once the ancestors, the cousins, and the younger brothers. When
the fishes of the Devonian age came out upon the land, the potentiality
of the higher methods of life first became manifest. With the new
conditions, more varied and more exacting, higher and more varied
specialization was demanded, and, in response to these new conditions,
from a fish-like stock have arisen all the birds and beasts and men that
have dwelt upon the earth.

[Illustration:

  FIG. 505.—Batfish, _Ogcocephalus vespertilio_ (L.). Florida.
]

[Illustration:

  FIG. 506.—Batfish, _Ogcocephalus vespertilio_ (Linnæus). Carolina
    Coast.
]

                                THE END.



                                 INDEX


 aal-mutter, ii, 144

 Abbott, i, 415, 419, 422; ii, 307, 534
   on perch, ii, 307

 abdominal fishes, ii, 39

 Abdominales, i, 393; ii, 38, 39

 Abeona, ii, 375

 Abramis, ii, 167
   figure of, ii, 168

 Aboma,
   figure of, ii, 462

 abundance of food-fish, i, 329

 abura-ainame, ii, 440

 abura-bodzu, ii, 323

 aburazame, i, 524

 Acantharchus, ii, 297

 Acanthistius, ii, 323

 Acanthobatis, i, 553

 Acanthocephala, i, 344, 351

 Acanthocepola, ii, 363

 Acanthoclinidæ, ii, 516

 Acanthoclinus, ii, 516

 Acanthocybium, ii, 266

 Acanthodei, i, 65, 437, 447, 513, 519, 545, 561
   Dean on, i, 517
   families of, i, 516
   order of, i, 514
   Woodward on, i, 514

 Acanthoëssidæ, i, 515, 516

 Acanthoëssus, i, 446, 510-513
   figure of, i, 515
   scales of, figured, i, 521

 Acantholabrus, ii, 387

 Acanthonemus, ii, 286

 Acanthopteri, ii, 157

 Acanthopterygian, ii, 39, 293

 Acanthopterygii, i, 391; ii, 189, 208-214

 Acanthostracion, i, 377

 Acanthuridæ, i, 206; ii, 405, 407, 410, 411
   family of, ii, 407

 Acanthurus, i, 268, 271; ii, 407, 409

 Acanus, ii, 330

 Acara, ii, 381

 Acentronura, ii, 236

 Acerina, ii, 241, 309

 Acentrophorus, ii, 23

 Achirinæ, ii, 495

 Achirus,
   figure of, ii, 496

 Acipenser, i, 291, 332, 391, 452; ii, 18, 19, 20, 22
   figure of, ii, 19, 20
   larva of, figured, i, 141

 Acipenseridæ, i, 290; ii, 18

 Acipenseroidei, i, 382

 Acraniata, i, 484

 Acrocheilus, ii, 169

 Acrogaster, ii, 252

 Acrognathus, ii, 34

 Acropoma, ii, 317

 Acropomidæ, ii, 317

 Acrotidæ, ii, 285

 Acrotus, ii, 285

 Actinistia, i, 602
   order of, i, 604

 Actinopteri, i, 451, 507, 599, 610; ii, 1, 2, 4, 5, 208

 Actinopterygii, i, 462; ii, 1

 Actinosts, ii, 1, 33

 actinotrichia, i, 80

 Adaptation of fishes, i, 177-225

 adaptive radiation,
   law of, i, 296

 adder-fish, ii, 501

 Adelfisch, ii, 65

 Adelochorda, i, 461

 Adinia, ii, 199

 adipose fin, i, 25

 Ægæonichthys, ii, 549

 Æoliscus,
   figure of, ii, 235

 Ærolepis, ii, 14

 Æthalion, ii, 41

 Ætheospondyli, ii, 24, 29

 Æthoprora,
   figure of, i, 188

 Aëtobatis, i, 557
   figure of, i, 558

 African catfish,
   figure of, i, 457; ii, 185

 Agassiz, A., i, 405

 Agassiz, L., i, 419, 428, 614; ii, 1, 39, 183, 486
   on dispersion, i, 284
   on Embiotocidæ, ii, 378, 379
   on embryology of garpike, ii, 31
   on fish fauna of N. E., i, 302
   on fossil fishes, i, 404
   on ganoids, ii, 9
   on high and low forms, i, 381
   on Lepidosteus, ii, 5
   on Onchus, i, 530
   portrait of, i, 399
   pupils of, i, 405
   questions raised by, i, 284
   sketch of, i, 404

 Age of fishes, i, 144-146

 agency of ocean currents, i, 243

 Agnatha, i, 508

 Agonidæ, i, 208; ii, 3, 185, 452, 453, 456
   family of, ii, 449

 Agonoid fish,
   figure of, i, 221; ii, 453

 Agonostomus, ii, 107, 222

 Agonus, i, 219; ii, 453

 Agrammus, ii, 440

 Ahl, i, 394

 aholehole, ii, 304

 air-bladder, i, 11
   air-duct, i, 12
   Aristotle on, 95
   Borelli on, i, 95
   of Carp, i, 93; ii, 159, 160
   in Cœlacanthus, i, 604
   defined, i, 92, 93
   De Fosse on, i, 97
   Delaroche on, i, 95
   figure of, i, 93, 604
   function of, i, 94
   in ganoids, i, 101
   gases in, i, 94
   in Labyrinthici, i, 91
   an organ of hearing, ii, 159
   origin of, i, 98
   position of, i, 35
   Sörensen on, i, 97
   Tower on, i, 95
   use of, i, 12
   wanting in sharks, i, 506
   Weber on, i, 96

 akadai, ii, 344

 Alaska blackfish, i, 51, 147, 290
   figure of, i, 149; ii, 206

 Alaska cod, ii, 536

 Alaska grayling,
   figure of, i, 328; ii, 120

 Alaskan rivers,
   fishes of, i, 304, 305

 Albacore, i, 210; ii, 136
   figure of, ii, 263
   Goode on, ii, 263
   long fin, ii, 263

 Albatross, the i, 263, 408; ii, 60, 130, 138

 Albatrossia, ii, 541

 Albula, i, 142, 205; ii, 29, 46, 148
   figure of, i, 147; ii, 44

 Albulidæ, ii, 41, 44

 Alburnus, ii, 167

 Alcock, i, 244, 408; ii, 290

 Aldrich,
   photograph by, i, 303

 Aldrovandi, i, 388

 Aldrovandia,
   figure of, ii, 138

 Alectis, i, 202; ii, 276

 aleihi, ii, 253

 Alepisauridæ, i, 134

 Alepocephalidæ, ii, 60

 Alepocephalus,
   figure of, ii, 60

 alewife, ii, 49
   figure of, ii, 50

 alfonsinos, ii, 251

 alimentary canal, i, 31

 alkaloid poisons, i, 182, 184, 185; ii, 411, 412

 allantiasis, i, 183

 alligator-fish, ii, 449, 453

 alligator-gar,
   figure of, ii, 31

 allmouth, ii, 545

 Alopiidæ,
   family of, i, 536

 Alosa, i, 204, 291; ii, 50

 Alticus,
   figure of, i, 230; ii, 509

 Alutera, i, 206; ii, 414, 415

 amadai, ii, 363

 Amanses, ii, 415
   figure of, ii, 414

 Amaræcium, i, 477

 Ambassis, ii, 317

 Ambassidæ, ii, 317

 amber-fish, ii, 272
   figure of, i, 458; ii, 273

 amber-jack, ii, 274

 Amblodon, i, 302

 Ambloplites,
   figure of, ii, 299
   skull of, figured, ii, 296

 Amblyopsidæ, 290; ii, 204
   family of, ii, 200

 Amblyopsis, i, 220, 314
   figure of, i, 221, 222; ii, 203

 Amblypterus, ii, 14

 Amblystoma, i, 78

 Ameiurus, i, 283, 293, 310, 356; ii, 35, 183, 185, 186, 299
   figure of, i, 344, 358; ii, 180, 181
   parasites of, i, 344

 American charr, ii, 110

 American fishes,
   Goode on, i, 335

 Amia, i, 33, 101, 102, 204, 291, 344, 391, 612, 623; ii, 8, 9, 11, 31,
    33, 36, 41, 160
   figure of, ii, 33, 35
   lower jaw of, ii, 33
   shoulder-girdle in, i, 86
   tail of, i, 82

 Amiatus, i, 394

 Amiidæ, i, 290; ii, 4, 34, 35, 36

 Amioidei,
   Lütken on, ii, 33

 Amiopsis, ii, 36

 Amitra, ii, 454

 Ammocœtes, i, 142

 Ammocrypta, ii, 306
   figure of, i, 158; ii, 313

 Ammodytes, ii, 224, 391, 514, 522
   figure of, ii, 521

 Ammodytidæ, ii, 215, 520, 521

 Amphacanthi,
   suborder of, ii, 409

 Ampheristus, ii, 436

 Amphibia, i, 393, 600, 606

 Amphibians, ii, 9
   origin of, i, 600

 Amphicœlian, i, 49

 Amphiodon, i, 394

 Amphioxides, i, 483

 Amphioxus, i, 482, 495

 Amphiplaga, ii, 243

 Amphipnoidæ, 11, 141

 Amphipnous, ii, 141

 Amphiprion, ii, 384

 Amphisile, ii, 235

 Amphisticus, ii, 375

 Amphistiidæ,
   family of, ii, 245, 247

 Amphistium, ii, 485
   figure of, ii, 247

 Amyzon, ii, 175

 Anabantidæ, ii, 215, 370
   Gill on, i, 366

 Anabas, i, 91, 103, 163
   figure of, ii, 366

 Anableps, i, 117, 391; ii, 131
   eye of, ii, 194
   figure of, i, 117
   Marsh on, ii, 194
   Nelson on, ii, 196

 Anacanthini, i, 405; ii, 484, 485, 499, 501, 532, 533, 538
   order of, ii, 532, 533

 anadromous fishes, i, 291

 anadromous salmon, ii, 68

 anal fin, i, 10
   in Embiotocidæ, i, 125
   as intromittent organ, i, 124
   in Pœciliidæ, i, 125
   in sword-tail minnow, i, 124

 analogy and homology, i, 368, 369
   Coues on, i, 369

 Anampses, ii, 390

 Anarhichadidæ, ii, 517

 Anarhichas, i, 208, 391; ii, 518
   figure of, ii, 517
   food of, ii, 518

 Anarchias, ii, 153

 Anarrhichthys, i, 208, 364; ii, 518
   skull of, ii, 517

 Anarthri, i, 509

 Anarthrodira, i, 584, 585, 590

 Anaspida, i, 573, 622
   order of, i, 579

 anatomy of tunicates,
   figure showing, i, 472

 Anchovia, i, 199, 205
   figure of, ii, 54

 anchovy,
   figure of, ii, 54

 anchovy, silvery,
   figure of, ii, 54

 ancient outlet of Lake Bonneville,
   photograph of, i, 303

 Ancylostylos, ii, 45

 Andaman Islands,
   fishes of, i, 166

 Andrews, i, 428

 Anema, ii, 504

 angel-fishes, i, 547, 549
   figure of, ii, 401, 404

 angler-fishes, i, 189, 206; ii, 542-553
   carpels of, i, 51
   figure of, i, 52
   Gill on, ii, 543
   habits of, ii, 543-545
   Kent on, ii, 543

 anglers,
   dorsal fin in, i, 202

 angling, i, 336
   Young on, i, 337-339

 Anguilla, i, 127, 162, 211; ii, 143
   figure of, ii, 142, 148

 Anguillidæ, i, 290; ii, 148
   family of, ii, 142

 angular, i, 606

 Anisotremus, i, 271; ii, 341

 Anomalopidæ,
   family of, ii, 317

 anko,
   figure of, ii, 545

 Anomalops, ii, 317

 Anoplogaster, ii, 252

 Anoplopoma,
   figure of, ii, 438

 Anoplopomidæ,
   family of, ii, 438

 Anoplus, i, 260; ii, 333

 Antechinomys, ii, 471

 Antennariidæ, i, 52; ii, 542, 549, 553
   Aristotle on, ii, 546
   deep-sea, ii, 548
   Goode on, ii, 545
   habits of, ii, 544-546
   Hoffmann on, ii, 546
   spawning of, ii, 546

 Antennarius, i, 197, 206
   figure of, ii, 550, 553

 Anthias, ii, 328

 Antiarcha, i, 573, 581, 590, 622
   order of, i, 576

 Antigonia, i, 262

 Anyperodon, ii, 328

 ao, ii, 274

 Apeltes,
   figure of, ii, 232

 Aphanopus, i, 210

 Aphareus,
   figure of, ii, 339

 Aphredoderidæ, i, 290; ii, 243, 294

 Aphredoderus, ii, 204, 252, 291, 294, 296
   figure of, ii, 295

 Apia,
   coral reef of, figured, i, 234

 Apichthys, ii, 278

 Aplidiopsis,
   figure of, i, 479

 Aploactis, i, 202

 Aplodactylidæ, ii, 363

 Aplodactylus, ii, 364

 Aplodinotus, i, 291, 302; ii, 354, 357

 Apocopodon, i, 558

 Apodes, i, 393, 611; ii, 40, 139-158, 532
   order of, ii, 141

 Apodichthys, i, 227; ii, 512

 Apogon,
   figure of, i, 455; ii, 316, 319

 Apogonidæ,
   family of, ii, 316

 Apomotis, i, 26, 310; ii, 301
   figure of, i, 27; ii, 350

 Apostasis, ii, 406

 Apostolides, i, 412

 Appendicularia, i, 466
   Brooks on, i, 480

 Appendiculariidæ, i, 474

 Aprion, i, 325; ii, 338

 Apsilus, ii, 338

 aquatic worms, ii, 143

 Aracana, ii, 417

 Arapaima, ii, 11, 56

 Arbaciosa,
   species of, ii, 531

 Archæomænidæ, ii, 29

 Archæus, ii, 278

 Archencheli,
   suborder of, ii, 141, 142

 archers, ii, 400

 archicercal tail, i, 81, 83

 archipterygium, i, 59-61, 68, 69, 73, 446, 459, 511, 512, 522, 598,
    600, 601
   Boulenger on, i, 79
   Gegenbaur on, i, 60
   Günther on, i, 60

 archnoid membrane, i, 109

 Archoplites, i, 179, 240; ii, 297
   figure of, i, 258

 Archosargus, i, 324; ii, 346
   figure of, i, 31; ii, 347

 Archoteuthis, ii, 410

 Arctic codling, ii, 537

 Arctic species,
   in lakes, i, 316
   Loven on, i, 317
   Malmgren on, i, 317
   Smith on, i, 317

 Arctoscopus, ii, 364

 Argentina, i, 391

 Argentinidæ, ii, 122, 124

 Argidæ, ii, 185

 Argyropelecus,
   figure of, i, 190; ii, 137

 Argyrosomus, i, 315; ii, 62, 65, 67
   figure of, ii, 66

 Ariscopus, i, 257
   figure of, ii, 504

 Aristotle, ii, 146
   on fishes of Greece, i, 387
   on noises of fish, i, 95

 Arius, ii, 178, 186

 arm of frog, i, 601
   figure of, i, 71

 ama-ama, ii, 221

 armado, i, 169

 arnillo, ii, 338

 Arnoglossus, ii, 488

 arrow-toothed halibut, ii, 491

 Artedi, i, 374, 390
   on genera, i, 391

 Artediellus, ii, 442

 Artedius, ii, 442

 Arthrodira, i, 573, 584, 585, 590, 612
   Dean on, i, 581
   Jækel on, i, 591

 Arthrodires, i, 204, 241, 436, 437, 603, 622; ii, 3
   classification of, i, 584
   figure of, i, 445, 584
   occurrence of, i, 583
   relationships of, i, 588

 Arthropteridæ, i, 553

 Arthropterus, i, 553

 Arthrognathi, i, 581, 584, 585, 589, 590
   Dean on, i, 584

 Arthrothoraci, i, 584, 586, 587

 articular, i, 606

 artificial impregnation,
   Jacobian method, i, 150

 Ascanius, i, 396; ii, 472

 Ascelichthys, ii, 449

 Ascidia,
   figure of, i, 474

 Ascidiacea, i, 474

 ascidians, i, 460, 467
   Kingsley on, i, 474
   Ritter on, i, 474

 Ascidiiæ, i, 474, 475

 Ascidina,
   figure of, i, 475

 Aseraggodes, ii, 496

 Ashmead,
   on leprosy transmission, i, 186

 Asineopidæ, ii, 243, 296, 317

 Asineops, ii, 243, 317

 Asmuss, i, 427

 Aspasma, ii, 531
   figure of, ii, 530

 Aspidocephali, i, 568, 575

 Aspidoganoidei, i, 568

 Aspidophoroides,
   figure of, ii, 453

 Aspidorhini, i, 568

 Aspidorhynchidæ, ii, 24, 29

 Aspidorhynchus, ii, 29

 Aspius, ii, 175

 Aspredo, ii, 184

 Aspro, ii, 307, 310
   figure of, ii, 309

 aspron, ii, 309
   figure of, ii, 310

 Asterolepidæ, i, 576, 623

 Asterolepis, i, 577, 591

 Asterospondyli, i, 447, 510, 513, 532
   order of, i, 525

 asterospondylous, i, 49

 Asterosteidæ, i, 584, 585

 Asterosteus, i, 585

 Asterropteryx, i, 263

 Astrodermiidæ, i, 551

 Astrodermus, i, 551

 Astrolabe, the, i, 408

 Astrolytes,
   figure of, ii, 442

 Astronesthidæ, ii, 128

 Astrape, i, 554

 Astroscopus, ii, 503
   Gilbert on, i, 187
   electric organs of, i, 187

 Asymmetron, i, 483; ii, 467

 Ateleaspis, i, 574

 Atheresthes, i, 205; ii, 491

 Atherina, i, 393; ii, 216

 Atherinidæ, i, 290; ii, 215

 Atherinops, ii, 218

 Atherinopsis,
   figure of, ii, 218

 Atherinosoma, ii, 218

 Athlennes, ii, 211

 Atka fish,
   figure of, i, 328; ii, 439

 Atka mackerel, ii, 439

 Atlantic creek, i, 308, 309

 Atlantic oarfish, ii, 472

 Atlantic salmon, ii, 89

 attenuate, i, 19

 Atthey, i, 426

 Auchenopterus, ii, 508

 atule, ii, 275

 auditory ossicles, ii, 160

 Aulichthys, ii, 233

 Aulolepis, ii, 48

 Aulopidæ, ii, 130, 132

 Aulopus, i, 259; ii, 190

 Aulorhamphus, ii, 406

 Aulorhynchidæ,
   family of, ii, 232

 Aulorhynchus, ii, 233

 Aulostomidæ,
   family of, ii, 233

 Aulostomus, ii, 233
   figure of, ii, 234

 Australia, ii, 363

 Australian flying-fish,
   figure of, i, 341

 Australian lung-fish, i, 100

 autochthonous, i, 245

 autostylic skull, i, 561; ii, 8

 Auxis, ii, 262

 awa, ii, 45, 221

 awaawa, ii, 43

 awaous, i, 254; ii, 465

 aweoweo, ii, 333

 Axinurus, ii, 409

 axonasts, i, 604, 605; ii, 17

 Ayres, i, 419, 428

 ayu, i, 256; ii, 115, 117, 118
   figure of, i, 321; ii, 116
   fishing for figured, i, 333, 335

 Azevia, i, 271; ii, 489

 d'Azyr, i, 390

 Azygostei, i, 581

 azygous, i, 88


 Baer, i, 428

 Bagarius, ii, 186

 bagonado, ii, 344

 bagre, ii, 182

 bagre de Rio, ii, 182

 Bagrus, ii, 183

 Baikal cods, ii, 455

 Baird, i, 419; ii, 142
   on bluefish, ii, 279-282
   on eel migrations, ii, 142
   portrait of, i, 407

 Bairdiella, ii, 355
   figure of, ii, 355

 Bakker, i, 428

 Balanoglossidæ, i, 465

 Balanglossus, i, 461

 Balanus, ii, 544

 balaos, ii, 212

 Balfour, i, 428, 511, 513; ii, 8
   finfold theory, i, 69, 514
   lateral-fold theory, i, 71-73
   on paired fins, ii, 8
   on sharks, i, 511

 Balfour and Parker,
   on Lepidosteus, ii, 5

 Balistapus, i, 181; ii, 413

 Balistes, i, 206, 391, 611; ii, 22
   figure of, i, 184; ii, 412

 Balistidæ, ii, 413, 418
   family of, ii, 412

 Ballou,
   on eels, ii, 417

 banded rockfish,
   figure of, ii, 432

 banded sunfish,
   figure of, ii, 299

 bandfishes, ii, 363

 bandfishes,
   the crested, ii, 291

 Banks, i, 395

 barbels, i, 115; ii, 170
   organs of touch, i, 122

 barber-fish, ii, 328

 barbero, ii, 408

 barbudos, ii, 256

 Barbulifer, ii, 462

 Barbus, ii, 170, 175

 Barkas, i, 426

 Barneville, i, 412

 Barracuda, ii, 34, 39, 215, 266, 317, 469

 Barracuda,
   family of, ii, 222
   figure of, ii, 223

 Barramunda, i, 116, 614, 615
   Günther on, i, 615

 barreto, ii, 467

 barriers,
   Alleghanies, i, 311
   artificial dams, i, 300
   Cape of Good Hope, i, 268
   checks to movement, i, 240
   crossing by fishes, i, 302
   to dispersion, i, 297
   Isthmus of Panama, i, 269
   local, i, 298
   mountain chains, i, 310
   Rocky Mountains, i, 305
   the Sierras, i, 310
   silt-bearing streams, i, 301
   species absent from, i, 239
   temperature, i, 298
   waterfalls, i, 300
   watersheds, i, 205

 basal bone,
   of dorsal fin, i, 49
   figure of, i, 49, 56
   of pectoral fin, i, 59

 baseosts, ii, 17

 basilar, i, 88

 Basilevsky, i, 411

 basking shark, i, 539
   figure of, i, 540
   largest of fishes, i, 539

 bass, i, 4, 21, 47, 290, 323, 440; ii, 316-350
   black, i, 303, 304
   white, i, 321
   yellow, i, 321

 bassalian fishes, i, 245, 246; ii, 128

 Bassani, i, 427

 Bassozetus,
   figure of, i, 456

 bastard halibut, ii, 489

 Bateson, i, 463

 batfish, ii, 402, 458
   figure of, ii, 553
   shoulder-girdle of, i, 88; ii, 551

 Bathyclupeidæ, ii, 290

 Bathygadus, ii, 541

 Bathylagus, ii, 127

 Bathymaster, ii, 502
   figure of, ii, 503

 Bathymasteridæ, ii, 502

 Bathyonidæ, ii, 540

 Bathyonus, ii, 540

 Bathypteroidæ, ii, 130

 Bathypterois, ii, 131

 Batoidei, i, 519
   suborder of, i, 549

 Batrachians, i, 85, 87, 88

 Batrachoides, i, 394; ii, 526

 Batrachoides,
   shoulder-girdle of, i, 59

 Batrachoididæ, i, 182, 192; ii, 525, 529, 542

 Batrachoids, ii, 529

 Batrictius, i, 394

 Bdellostoma, i, 490

 Beagle, the, i, 408

 Bean, i, 408, 419

 Beardslee, ii, 101

 Beardslee trout, ii, 101

 Belemnobatis, i, 551

 Bellotti, i, 412

 bellows fish, ii, 545

 Belon,
   on fishes of Mediterranean, i, 388

 Belone, ii, 210, 211

 Belonidæ,
   family of, ii, 210

 Belonorhynchidæ, ii, 514

 Belonorhynchus, ii, 17

 Belostomus, ii, 29

 Bembradidæ, ii, 441, 499

 Bembras, ii, 441

 Benecke,
   on spawning of eels, ii, 146

 Beneden, i, 427

 benimasu, ii, 72

 Bennett, i, 408, 416

 Bentenia, ii, 286

 Benthosauridæ, ii, 130

 Benthosaurus, ii, 131

 Berg, i, 415
   portrait of, i, 409

 Berndt,
   opah taken by, ii, 244
   photograph by, i, 323

 Berycidæ, i, 206; ii, 294, 499
   family of, ii, 251

 Berycoidei, ii, 40, 245, 290, 484, 485
   suborder of, ii, 250-257

 Berycoid fishes, ii, 250
   figure of, i, 439; ii, 253
   Starks on, ii, 250

 Berycoids, ii, 247

 Berycopsis, ii, 285

 Beryx, i, 259, 263, 438; ii, 249, 289
   figure of, ii, 251

 beshow, ii, 438

 Betta, i, 163; ii, 370

 biajaiba, ii, 336

 Bianconi, i, 412

 Bibron, i, 412

 big-eye, ii, 333
   figure of, ii, 332

 big-eyed scad, ii, 275

 Birkenia, i, 580
   figure of, i, 579

 Birkeniidæ, i, 579

 bishop-fish, i, 361

 bishop-fish,
   figure of, i, 361

 Björnson,
   on fishing villages of Norway, i, 329

 black angel, ii, 405

 black angel-fish,
   figure of, ii, 403

 black bass, i, 209; ii, 168, 301, 328
   Hallock on, ii, 302
   Henshall on, ii, 302
   large-mouthed, ii, 304
   small-mouthed, ii, 303

 black bream, ii, 206

 Black Current of Japan, sharks in, i, 536

 black escolar, 338

 black-fin snapper, ii, 336

 blackfish, ii, 387

 black grouper, ii, 323, 325

 black-horse, ii, 173

 Blackiston's line,
   relation to fishes, i, 257

 black-jack, ii, 276

 black nohu,
   figure of, i, 180; ii, 436
   stinging spines of, i, 180

 black-nosed dace,
   figure of, i, 342; ii, 164
   parasites on, i, 342

 black rockfish, ii, 429

 black ruff, ii, 284

 black sea-bass, ii, 329

 black-sided darter,
   figure of, ii, 311

 blacksmith, ii, 381

 black-spotted sailor's choice, ii, 341

 black-spotted trout, ii, 95

 black swallower,
   figure of, i, 29; ii, 360

 black tai, ii, 344

 black will, ii, 328

 black wrasse, ii, 387

 Blainville, i, 400
   on Palæoniscum, ii, 14

 Blake, i, 60, 408

 Blanchard, i, 412

 blanquillos, ii, 361, 362

 blastoderm, i, 135

 blastomeres, i, 135

 blastopore, i, 138

 blastula, i, 131, 132

 bleak, ii, 163, 167

 Bleeker, i, 376, 412, 414

 Bleekeria, ii, 521

 Bleekeriidæ, ii, 522

 Blenniidæ, i, 208, 276, 290; ii, 506-531

 Blennioidea, ii, 470

 Blennius, i, 208, 391; ii, 511, 513

 Blennius,
   figure of, i, 508

 blenny, i, 209, 230, 290, 429; ii, 507-531
   figure of, ii, 509, 511
   Japanese, i, 9; ii, 513
   kelp, ii, 507
   northern, ii, 511
   sarcastic, ii, 507
   snake, ii, 512

 Blepsias,
   figure of, ii, 448

 blind Brotula,
   figure of, i, 222

 blind catfish, ii, 181

 blind cavefish,
   figure of, i, 116; ii, 202

 blindfish, i, 290; ii, 202, 524
   descent of, ii, 202
   Eigenmann on, i, 117; ii, 202
   habits of, ii, 202
   theories regarding origin, ii, 202

 blindfish of Mammoth Cave, ii, 202, 203
   Eigenmann on, i, 221, 222
   figure of, i, 221

 blind goby, ii, 467

 blob, ii, 444

 Bloch, i, 389, 397

 Blochiidæ, ii, 514

 Blochius,
   figure of, ii, 514

 Blossom, the, i, 408

 blue-back, ii, 71, 73-76

 blue-back salmon, ii, 68, 69

 blue-breasted darter, i, 231; ii, 314
   figure of, i, 231

 blue cod, ii, 440

 bluefin, ii, 66

 bluefin cisco,
   figure of, ii, 66

 bluefish, ii, 278, 354
   Baird on, i, 279-282
   destructiveness of, ii, 281
   figure of, i, 324; ii, 279
   food of, ii, 280

 bluegill,
   figure of, ii, 300

 blue-green sunfish, i, 26
   figure of, i, 27; ii, 350

 blue parrot-fish, ii, 396
   figure of, ii, 394
   figure of jaws, ii, 393

 blue sharks, i, 534, 542

 blue smelt,
   figure of, ii, 218

 blue-spotted guativere, ii, 324

 blue surf-fish, ii, 375

 blue tang, ii, 408
   figure of, ii, 407

 Blyth, i, 396

 boarfishes, ii, 135, 398

 bobo,
   figure of, ii, 222

 boccaccio, ii, 429

 Bocage, i, 414

 Bocourt, i, 412

 Bodianus, i, 207, 271; ii, 388

 boga, ii, 347, 348

 Bogoslovius, ii, 541

 Bohr, i, 97

 Boleophthalmus, ii, 465
   figure of, i, 118; ii, 466

 Boleosoma, i, 302; ii, 313

 Bollman, i, 420

 Boltenia, i, 475

 Bombay-duck, ii, 131

 bonaci-arará, ii, 325

 bonaci-cardenal, ii, 325

 Bonaparte, i, 412

 bones of the fish,
   actinosts, i, 42
   alisphenoid, i, 38, 39, 40, 53
   anal fin, i, 48
   angular, i, 42, 43, 54
   articular, i, 42, 43, 54
   basibranchial, i, 46
   basihyal, i, 42, 45
   basioccipital, i, 36, 38, 39, 40, 53
   basisphenoid, i, 36, 38, 39, 53
   branchiostegals, i, 42, 45
   carpals, i, 51
     of anglers, i, 51
   caudal fin, i, 48
   caudal vertebræ, i, 48
   ceratobranchial, i, 46
   ceratohyal, i, 42, 45
   clavicle, i, 42, 50, 52
     figured, i, 52
   coracoid, i, 50, 51
     of cranium, i, 39
   dentary, i, 42, 43, 54
   dorsal fin, i, 48
   epihyal, i, 42, 45
   epibranchial, i, 46
   epioccipital, i, 36
   epiotic, i, 36, 37, 38, 39, 40, 53
   epipleurals, i, 48
   ethmoid, i, 36, 37, 53
   exoccipital, i, 36, 37, 38, 39, 40, 53
   frontal, i, 36, 37, 38, 53
   glossihyal, i, 42
   hæmal spine, i, 48
   hæmaphysis, i, 48
   hyoid arch, i, 42
   hyomandibular, i, 42, 44, 54
   hypercoracoid, i, 42, 52
   hypobranchial, i, 46
   hypocoracoid, i, 42, 43, 52
   hypural, i, 48, 49
   infraclavicle, i, 51
   interclavicle, i, 51
   interhæmals, i, 49
   interhyal, i, 42, 45
   interneural, i, 48
   interopercle, i, 42, 45, 54
   interspinals, i, 49
   isthmus, i, 45
   maxillary, i, 41, 42
   mesopterygoid, i, 41, 42
   metapterygoid, i, 41, 42, 54
   nasal, i, 42, 53
   neural spine, i, 48
   neuropophysis, i, 48
   opercle, i, 42, 54
   opisthotic, i, 36, 37, 38, 39, 40
   palatine, i, 41, 42, 54
   parapophysis, i, 48
   parietal, i, 36, 37, 39, 40, 53
   parsasphenoid, i, 36, 38, 53
   pectoral fin, i, 42
   pelvic girdle, i, 42
   pharyngeals, i, 46, 47
     figure of, i, 47
     lower, i, 46
     suspensory, i, 46
     upper, i, 46
   postclavicle, i, 42, 51
     figured, i, 52
   postero-temporal, i, 50
   post-temporal, i, 42, 52
   prefrontal, i, 36, 37, 38, 53
   premaxillary, i, 42
   preopercle, i, 42, 54
   preorbital, i, 41, 42
   prootic, i, 36, 38, 53
   proscapula, i, 50
   pterotic, i, 36, 37, 38, 39, 40, 53
   pterygials, i, 51
   pterygoid, i, 41, 42, 54
   quadrate, i, 42, 43, 54
   ribs, i, 48
   scapula, i, 50
   shoulder-girdle, i, 42, 50, 51, 52
   sphenotic, i, 36, 37, 38, 53
   subopercle, i, 42, 54
   suborbital, i, 42
   supraclavicle, i, 42, 50
   supraoccipital, i, 36, 37, 38, 53
   suprascapula, i, 50
   supratemporal, i, 42, 50
     figured, i, 51
   symplectic, i, 42, 54
   urohyal, i, 42, 54
   ventral fin, i, 42
   vomer, i, 36, 37, 38, 53
   zygapophysis, i, 48

 bonito, ii, 264

 bonnaterre, i, 397

 bony fish, i, 204, 454, 506; ii, 37
   classification of, ii, 38
   development of, i, 135
   figure of, ii, 438
   specialized, figured, i, 456

 bony scales, i, 21

 Boops, i, 260, 267; ii, 348, 350

 Borassus, ii, 367

 Borelli, i, 390
   on air-bladder, i, 95

 Boreogadus, ii, 537

 botolism, i, 183

 Bothinæ, ii, 487

 Bothriocephalus, i, 345

 Bothriolepis, i, 577

 Bothus, ii, 486

 Botryllidæ, i, 476

 Botryllus, i, 476; ii, 545
   figure of, i, 477, 478, 479

 bottle-nosed chimæra,
   eggs of, figured, i, 127

 Bougainville, i, 395

 Boulenger, i, 360, 364, 370, 414, 428, 513, 600, 601, 606, 608, 609;
    ii, 41, 48, 128, 129, 136, 138, 158, 190, 485, 502, 522, 551
   on Archipterygium, i, 79
   on Galaxias, ii, 205
   catalogue of fishes, i, 402
   on opahs, ii, 243
   portrait of, i, 403
   on vertebræ, i, 213
   on zooid fishes, ii, 245

 Bovichthyidæ, ii, 502

 bowfin, i, 290, 440; ii, 33, 34
   figure of, ii, 35
   tail of, figured, i, 82

 Bowring,
   on noises by fishes, i, 168

 Brachydirus, i, 590

 Brachyistius, ii, 375

 Brachymystax, ii, 62, 67

 brain,
   of chimæra, i, 410, 411
   figures of, i, 110, 111
   Günther on, i, 109
   in hagfish, i, 112
   of lamprey, i, 112
   of perch, i, 111
   of pike, i, 109
   of primitive fishes, i, 112
   reflex action of, i, 153
   of shark, i, 110, 111

 Brama, ii, 135, 286

 Bramidæ, ii, 291
   family of, ii, 286

 branch herring, ii, 49

 branchial bones, i, 46

 Branchiostegi, i, 391

 Branchiostoma, i, 34, 35, 120, 383, 483
   eggs of, i, 131
   figure of, i, 484

 Branchiostomidæ, i, 484

 Brandt, i, 412

 Branner, i, 415

 Brayton, i, 420

 bream, ii, 163, 167

 Bregmaceros, ii, 524

 Bregmacerotidæ, ii, 524

 Brevoort, i, 416

 Brevoortia, ii, 51
   figure of, i, 340; ii, 51

 brit, ii, 216, 217

 broad-shad, ii, 347

 broad-soles, ii, 495

 Brongniart, i, 427, 428

 brook lamprey,
   figure of, i, 120, 505
   larva of, figured, i, 492
   mouth of, figured, i, 492

 Brooks,
   on Appendicularia, i, 480

 brook trout, ii, 99, 107, 108, 110, 113, 115
   figure of, ii, 111

 Brosme, ii, 539

 Brosmius, ii, 539

 Brosmophycis, ii, 524

 Brotula,
   figure of, ii, 524
   blind, figured, ii, 524

 Brotulidæ, i, 314; ii, 523, 533

 Brotulids, ii, 39, 524

 Broussonet, i, 396

 Brown, i, 426

 Browne, i, 389

 brown tang,
   figure of, i, 181; ii, 408

 Brünnich, i, 394

 Bryactinus, i, 565

 Brycon,
   figure of, ii, 162

 Bryostemma,
   figure of, ii, 511, 514

 Bryttosus, i, 256; ii, 297, 320

 buccal cirri, i, 595

 Buchanan,
   on hunting of Chaca, i, 170

 Buckland, i, 423
   on soles, ii, 497
   on turbot roe, ii, 488

 Bucklandium, ii, 186

 budai, ii, 390

 buffalo-cod, ii, 440

 Buffalo Creek, i, 309

 buffalo-fish, ii, 160, 172
   figure of, ii, 173
   shoulder-girdle of, i, 51

 buffalo sculpin,
   figure of, ii, 443

 bulbus arteriosus, ii, 10, 11

 bullhead, i, 356

 bullhead shark,
   figure of, i, 526

 bumpers, ii, 276

 Bunocephalidæ, ii, 184

 burbot, i, 209; ii, 538
   figure of, ii, 539

 Bürger, i, 414

 butter-fish, ii, 283, 284, 324, 512

 butterfly fish, i, 440; ii, 381
   figure of, i, 143; ii, 402

 butterfly ray, i, 556

 butterfly sculpin,
   figure of, i, 288


 caballerote, ii, 335

 cabezon, ii, 442

 cabra mora,
   figure of, i, 20

 cabrilla, ii, 324, 328, 329

 cachucho,
   figure of, ii, 337

 Cælorhynchus,
   figure of, ii, 541

 Cæsio, ii, 342

 cagon de le alto, ii, 337

 cají, ii, 336

 Calamoichthys, i, 76, 89, 608

 Calamostoma, ii, 236

 Calamus, i, 49, 238; ii, 344
   figure of, ii, 345, 347

 calico-bass, ii, 297

 calico-salmon, ii, 72

 California lancelet,
   figure of, i, 484

 California miller's thumb,
   figure of, ii, 446

 California hake,
   figure of, ii, 540

 California pampano, ii, 283

 California sucker,
   figure of, ii, 174

 Callbreath,
   on running of salmon, ii, 86

 Callechelys, ii, 150

 Callichthyidæ, ii, 185

 Callichthys, i, 290

 calling the fishes, i, 167, 168
   in Indian temples, i, 167
   in basins of Tuileries, i, 167

 Callionymidæ, ii, 506

 Callionymus, i, 246, 257, 259, 263, 393, 500, 504

 Callipterygidæ, ii, 501

 Callipteryx, ii, 501

 Calliurus, i, 302

 Callorhynchus, i, 565, 566
   egg of figured, i, 127

 Callorhinus, ii, 537

 Calotomus, ii, 390, 391

 Camper, i, 389

 Campostoma, ii, 164
   figure of, i, 33; ii, 167

 Campyloprion, i, 529

 candil, ii, 255

 candle-fish, ii, 124

 Canestrini, i, 412

 Canobius, ii, 14

 Canthidermis, ii, 413

 Canthigaster, i, 206

 Cantor, i, 416
   on fighting-fish, i, 163

 Cape of Good Hope,
   as barrier, i, 269

 capelin,
   figure of, ii, 126

 capello, i, 414

 capitaine,
   figure of, ii, 387

 Capros, ii, 135, 398, 400

 Caracanthidæ, ii, 438

 Carangidæ, i, 144, 149, 210; ii, 15, 278, 470
   family of, ii, 272

 Carangopsis, ii, 278

 Carangus, i, 169, 324; ii, 275, 276, 285

 Carapidæ, ii, 522

 Caraproctus, ii, 455

 Carapus, ii, 520, 522

 Carassius, ii, 171
   figure of, i, 151

 Caranx, ii, 245, 275, 470, 542

 Carboniferous,
   fishes, i, 437
   sharks, i, 224

 Carcharias, i, 447, 534, 543; ii, 468
   figure of, i, 542

 Carchariidæ, i, 532, 534, 540, 542, 543

 carcharioid sharks, i, 540

 Carcharodon, i, 538

 Carcharopsis, i, 522

 cardenal, ii, 316

 cardiform teeth, i, 29

 cardinal fishes, the, ii, 316
   figure of, i, 455; ii, 316, 319

 cardinal vein, i, 108

 Carencheli, ii, 140, 153, 155

 caribe,
   Günther on, ii, 161

 carnivorous fishes, i, 29

 carp, i, 21, 53, 93, 290; ii, 162, 164
   air-bladder of, figured, ii, 160
   native of China, ii, 170
   domestication of, ii, 170

 Carpiodes, i, 302
   figure of, ii, 173

 carp-sucker,
   figure of, ii, 173

 carrying eggs in mouth, i, 170-173
   by catfish, i, 170

 casabe, ii, 276

 Cassiquiare,
   Branner on, i, 307
   crossing by fishes, i, 307

 Castelnau, i, 415

 Castour, i, 396

 Castro,
   photograph by, ii, 522

 catadromous fishes, i, 162, 291; ii, 143

 Catalina flying-fish,
   figure of, ii, 214

 catalineta, ii, 341

 Catalogue,
   of Panama fishes, i, 272

 catalufa de lo alto,
   figure of, ii, 289

 catalufa, ii, 288, 333
   figure of, ii, 331

 Catesby, i, 389

 catfish, i, 4, 20, 53, 119, 122,128, 169, 290, 440; ii, 159, 160,
    177-187
   African, ii, 185
   channel, ii, 179
   clavicle in, i, 87
   Cope on, i, 180
   descent from, ii, 186
   destroyed by lampreys, i, 357
   electric, ii, 183
   electric, figured, i, 186
   fossil, ii, 186
   of India, ii, 184
   Japanese, ii, 183
   Old World, ii, 182
   poison glands of, i, 180
   poison spine of, i, 179
   shoulder-girdle in, i, 86
   spines of, i, 179
   transfer to Sacramento, i, 310

 Catopteridæ, ii, 16

 Catopterus, ii, 16

 Catostomidæ, i, 46, 290; ii, 172, 175
   family of, ii, 171
   figure of, i, 315

 Catostomus, i, 198, 283, 302, 304, 316, 346; ii, 56
   figure of, i, 348; ii, 171
   pharyngeal teeth of, ii, 175

 cat shark, i, 533

 Catulus, i, 533

 caudal fin, i, 10

 caudal lancet, ii, 409

 Caularchus,
   figure of, i, 198, 531

 Caulolatilus, ii, 362

 Caulolepis, ii, 252, 253

 Caulophryne,
   figure of, i, 276, 548

 causes of dispersion, i, 318

 cavalla, ii, 266, 272-292

 cavefish, ii, 201, 523, 524
   Eigenmann on, ii, 524
   figure of, i, 117

 Cebedichthys, ii, 512

 Centaurus,
   larva of figured, i, 143

 centers of distribution, i, 244

 Centrarchidæ, i, 209, 232, 290; ii, 304, 320, 327, 380
   family of, ii, 297

 Centrarchus, i, 302; ii, 297

 Centriscidæ, ii, 227, 235
   family of, ii, 234

 Centriscus, i, 393; ii, 235

 Centrogenys, ii, 320

 Centrolepis, ii, 14

 Centrolophiidæ, ii, 283

 Centrolophius, i, 260; ii, 286

 Centrophoroides, i, 546

 Centrophorus, i, 546

 Centropomidæ, ii, 319

 Centropomus, i, 271, 273; ii, 309
   figure of, i, 324; ii, 319

 Centropristes, i, 136; ii, 328, 329
   eggs of, figured, i, 135

 Centroscymnus, i, 546

 Centrolabrus, ii, 387

 Cephalacanthidæ, i, 208
   family of, ii, 458

 Cephalacanthus, ii, 458
   figure of, ii, 456

 Cephalaspidæ, i, 576, 623

 Cephalaspis, i, 444, 569, 571
   figure of, i, 576, 577, 579

 Cephalopholis, ii, 324, 325

 Cephaloscyllium, i, 197

 Cepola, i, 260, 264, 393; ii, 363

 Cepolidæ, the, ii, 363

 Ceratacanthus, ii, 414

 Ceratias,
   figure of, ii, 548

 Ceratiidæ, i, 276

 Ceratobatis, i, 560

 Ceratocottus, ii, 443

 Ceratodontidæ, i, 600, 612
   family of, i, 613

 Ceratodus, i, 77, 85, 613-616

 Ceratoscopelus,
   figure of, ii, 133

 Ceratiidæ, ii, 547-549

 Cerdale, i, 271

 Cerdalidæ, ii, 516

 cestodes, i, 344

 Cestraciont shark, i, 526, 527, 530
   Eastman on, i, 529
   teeth, figured, i, 527

 Cestraciontes, i, 438, 519, 566
   Eastman on, i, 529
   families of, i, 528
   suborder of, i, 526
   teeth of figured, i, 527, 529

 Cetomimidæ, ii, 132

 Cetomimus,
   figure of, ii, 132

 Cetorhinus,
   figure of, i, 540

 Cetorhinidæ,
   family of, i, 539

 Cette, i, 396

 Chaca, i, 170

 Chacidæ, ii, 184

 Chænobryttus, i, 302; ii, 300

 Chætobranchus, ii, 381

 Chætodipterus,
   figure of, i, 325, 401

 Chætodon, i, 235, 242, 267, 391; ii, 400, 403, 405, 406
   figure of, i, 143; ii, 402

 Chætodontidæ, i, 206; ii, 245, 291, 381, 398, 402, 404, 405

 Chætodonts, ii, 247

 Chalacodus, i, 566

 Challenger, the, ii, 60, 130

 Champsodon, ii, 361

 Champsodontidæ, ii, 361

 Chanos, i, 205; ii, 221
   figure of, ii, 45

 Chanidæ,
   family of, ii, 44

 Channa,
   figure of, ii, 370

 channel bass, ii, 355

 channel catfish,
   figure of, i, 280

 channel-cats, the, ii, 179, 182

 Channomuræna, ii, 153

 Chanoides, ii, 44

 Chapala Lake,
   fishes of, ii, 216

 Characidæ, ii, 161, 162

 Characin, i, 290

 Characinidæ, i, 205, 290; ii, 381

 Characins, ii, 61, 160-162, 186

 Characodon, ii, 201

 characters,
   of Elasmobranchs, i, 507
   of species, i, 292

 Charitosomus, ii, 56

 charr, ii, 67, 99, 107, 114, 122

 Charlevoix, ii, 64

 Chasmistes, i, 304, 316; ii, 172

 Chasmodes, ii, 509

 Chauliodontidæ, ii, 129

 Chauliodus,
   figure of, ii, 129

 Chaunax, ii, 551

 Cheilio, ii, 390

 Cheilinus, ii, 390

 Cheilodipteridæ,
   family of, ii, 278

 Cheilodipterus, ii, 278
   figure of, ii, 279

 Cheiracanthus, i, 517

 Cheirodopsis, ii, 15

 Cheirodus, ii, 14

 Cheirolepis, ii, 14

 Chelidonichthys, i, 260; ii, 456

 Chelmo, ii, 404

 Chelonichthyidæ, i, 586

 Chelonopsis, ii, 425

 Chonerhinus, ii, 419

 cherna, ii, 324

 chevron, ii, 89

 chiasma, ii, 4

 Chiasmodon, ii, 136
   figure of, i, 29; ii, 360

 Chiasmodontidæ, ii, 215, 360

 Chilobranchidæ, ii, 141

 Chilomycterus,
   figure of, ii, 423

 Chiloscyllium, i, 56, 533
   pectoral fin of, i, 66

 Chimæra, i, 23, 35, 85, 204, 393, 435, 437, 448, 507, 509, 512-514,
    545, 561-567, 595, 610
   of California, i, 564
   Dean on, i, 563
   figure of, i, 449, 564, 565
   Parker on, i, 563

 Chimæridæ,
   family of, i, 564

 Chimæroids, i, 224, 583

 Chimæropsis, i, 566

 China fish,
   snake-headed, ii, 371

 Chinese whitebait, ii, 127, 128

 chinook, ii, 69

 chirivita, ii, 405

 Chirocentridæ, ii, 46

 Chirocentrus, ii, 46, 48

 Chirolophis, ii, 512

 Chiropterygium, i, 600, 605

 Chirostoma,
   figure of, i, 329; ii, 217

 Chirothricidæ, ii, 133

 Chirothrix,
   figure of, ii, 46, 134

 chisel-mouth, ii, 169

 Chlamydoselachidæ,
   family of, i, 525

 Chlamydoselachus, i, 361, 447, 448, 509, 521, 536
   figure of, i, 523

 Chlarias, i, 98, 290; ii, 186, 187
   figure of, i, 457; ii, 185

 Chlariidæ, ii, 184, 185

 Chlevastes, ii, 150
   figure of, i, 232

 Chloropthalmus, i, 260; ii, 130

 Chloroscombrus, ii, 276

 chochouwo, ii, 403

 chogset, ii, 387

 Chologaster, i, 203, 204, 223
   Eigenmann on, ii, 203
   figure of, i, 116; ii, 201
   Garman on, ii, 202
   Hoppin on, ii, 203

 Chondrenchelys, i, 521

 Chondropterygians, i, 508

 Chondropterygii, i, 391

 Chondrostei, i, 623, 624; ii, 2, 5, 13
   order of, ii, 17

 Chondrosteidæ, ii, 17, 18

 Chondrosteus, i, 622

 Chonerhinidæ, ii, 419

 Chopa, ii, 344, 350
   figure of, ii, 349

 Chordata, i, 460

 Chordate animals, i, 460
   lowest forms figured, i, 465

 Chordates, i, 508, 584, 597; ii, 1

 Chorisochismus, ii, 531

 Chriodorus, ii, 212

 Chromides,
   suborder of, ii, 380

 Chromis, i, 166; ii, 381

 Chrondrosteus,
   figure of, ii, 18

 Chrosomus, i, 304; ii, 164, 167

 chub, ii, 118, 147, 163
   figure of, ii, 169
   of Great Basin, ii, 169
   of Pacific, ii, 169

 chub of Great Basin,
   figure of, i, 287

 chub-mackerel, i, 94

 chub-sucker, i, 292
   figure of, i, 315; ii, 172

 chum, ii, 72

 cichla, ii, 380

 Cichlasoma, ii, 381

 cichlid, i, 290

 Cichlidæ, i, 209, 290; ii, 380, 381
   organs of smell in, i, 115

 cigar-fish, ii, 274

 ciguatera, i, 182-185; ii, 335, 411, 413

 Cimolichthys, ii, 133

 Ciona, i, 481

 Cirrhilabrus, ii, 390

 Cirrhitidæ, the, ii, 363, 426

 Cirrhitus, i, 271
   figure of, ii, 364

 Cirrostomi, i, 482, 595

 cisco, ii, 65

 Citharichthys, i, 274; ii, 489

 Citharinus, ii, 162

 Citula, i, 202; ii, 276

 Cladistia, i, 602
   order of, i, 605

 Cladodontidæ, i, 520, 522

 Cladodus, i, 65, 80, 437
   pectoral fin of, i, 521
   shoulder-girdle in, i, 521
   teeth of, figured, i, 522

 Cladoselache, i, 64, 66, 79, 80, 437, 446, 448, 510, 571, 573, 623
   Dean on, i, 518
   figure of, i, 65, 514, 515
   primitive character of, i, 514
   teeth of, figured, i, 515
   ventral view of, i, 515

 Cladoselachidæ, i, 514
   family of, i, 523

 clam-cracker, i, 556

 Clark,
   on eulachon, ii, 125

 Clarke, i, 416

 claspers, i, 124, 125

 classification,
   Coues on, i, 370
   of Elasmobranchs, i, 509, 510
   of fishes, i, 367-386
   of instincts, i, 154
   morphological, i, 371
   natural, i, 370
   terms used in, i, 462

 Clastes,
   Eastman on, ii, 32

 Clavellinidæ, i, 475

 clavicle,
   figure of, i, 87
   of sea catfish, i, 87

 Claypole, i, 426
   portrait of, i, 409

 cleavages, i, 135

 Clepticus, ii, 388

 Clidoderma, ii, 494

 Climatius, i, 446
   figure of, i, 518

 climbing-fish, ii, 367

 climbing-perch,
   figure of, ii, 366

 clingfish, ii, 529
   figure of, i, 198; ii, 531
   Günther on, ii, 529, 530
   sucking-disk in, i, 198

 Clinocottus, ii, 448

 Clinton, ii, 64

 Clinus, i, 208; ii, 507, 511, 513, 516

 Cloquet, i, 397

 Cloudy Bay cod, ii, 520

 Clupanodon, ii, 53

 Clupea, i, 204, 329, 391
   figure of, i, 331, ii, 49

 Clupeidæ, i, 204, 290; ii, 49, 52, 53

 clupeiform, ii, 11

 clupeoid, ii, 10

 Clupeidea, the, ii, 41

 coalfish, i, 209; ii; 438, 537

 Coal measures,
   fishes of, i, 223
   teeth found in, i, 65

 Costa, i, 412

 coast lines,
   effect on distribution, i, 248

 cobbler-fish, ii, 276

 cobia, ii, 282

 Cobitidæ, ii, 175, 185

 Cobitis, i, 391; ii, 176

 Cobitopsidæ,
   family of, ii, 224

 Cobitopsis,
   figure of, ii, 224

 Coccoderma, i, 605

 Coccosteans, i, 581

 Coccosteidæ, i, 622, 623, 584, 586

 Coccosteus, i, 583, 584, 587, 590, 593, 596, 623
   figure of, i, 582

 cochino, ii, 413

 Cochliodontidæ, i, 530
   family of, i, 531

 Cochliodus,
   lower jaw figured, i, 531

 cock-and-hen paddle, ii, 453

 cock-of-palace-under-sea, ii, 472

 cockeye pilot,
   figure of, ii, 382

 Coccolepis, ii, 14

 cod, ii, 51

 codfish, i, 122, 128, 290; ii, 481, 501, 532, 533
   figure of, i, 331; ii, 535
   Gill on, ii, 534
   Goode on, ii, 534
   pectoral fin of, i, 66
   reproduction of, ii, 535
   Sars on, ii, 535

 codling, ii, 538

 Cœlacanthidæ, i, 605

 Cœlacanthus,
   figure of, i, 604

 Cœlolepia, i, 573

 Cœlodus, ii, 22

 Cœlolepidæ, i, 573

 coho, ii, 72

 collection of fishes, i, 429-434
   by explosives, i, 430
   by poison, i, 430
   tackle for, i, 430

 Collett, i, 408, 427
   portrait of, i, 403

 Collie, i, 564

 Collins,
   on catastrophe to tilefishes, ii, 362
   on halibut, ii, 490

 Cololabis, ii, 212

 Colocephali, ii, 140-142, 153
   suborder of, ii, 152

 Colomesus, ii, 421

 Colorado trout,
   figure of, ii, 106

 colors of fishes, i, 226-236
   of coral-fishes, i, 235
   fading of, in spirits, i, 235
   intensity of, i, 232
   nuptial, i, 230
   protective, i, 226-229
   sexual, i, 230
   variation of, i, 235

 Columbia,
   figure of, ii, 242

 Comephoridæ, the, ii, 455

 Comephorus, ii, 524

 Commerson, i, 395

 commissure, i, 112

 common eel,
   figure of, ii, 143

 common skate,
   figure of, i, 552

 common sucker,
   figure of, ii, 174

 common sunfish,
   figure of, i, 7, 13; ii, 301

 conceptions of genus, i, 375

 Conchopona, i, 613

 conclusions,
   of Cope on dispersion, i, 286
   of Evermann, i, 274
   of Hill, 277-279
   as to Isthmus of Suez, i, 269
   of Jenkins, i, 274

 conger eels, ii, 149, 151
   figure of, ii, 150

 Congiopodidæ, ii, 436

 Congiopus, ii, 436

 Congo River,
   fishes from, i, 78, 607

 Congriopus, ii, 514

 Congrogadidæ, ii, 519

 Connoly,
   on calling fishes, i, 168

 Conocara, ii, 60

 Conodontes, i, 487
   figure of, i, 488

 Conorhynchus, i, 128

 constantino, ii, 320

 Cooper, i, 419
   on long-jawed goby, ii, 463

 Cope, i, 84, 311, 419, 428, 512, 602; ii, 1, 4, 13, 24, 35, 56, 159
   on classification, i, 406
   conclusions of, 286
   on dispersion, i, 286, 287
   on eels, ii, 139
   on fossil forms, ii, 32
   on isocercal tail, i, 84
   on ostracophores, ii, 569
   portrait of, i, 407
   sketch of, i, 406

 Copeland, i, 420
   portrait of, i, 421

 Copelandellus, ii, 315

 Coquille, i, 408

 coracoid, i, 88, 90

 coraco-scapular, i, 87

 coral reefs,
   at Apia, figured, i, 234
   fishes of, i, 235, 297
   fish life in, i, 215

 Corax,
   teeth of, figured, i, 543

 Coregoni, ii, 67

 Coregonus, i, 291, 305, 316, 322, 391; ii, 62, 65, 439
   figure of, i, 321; ii, 63

 Coreoperca, ii, 320

 Coris, ii, 390

 cormorant-fishing, ii, 116-119
   illustrations of, i, 333, 335

 cornet-fishes, ii, 390
   family of, ii, 233

 Cornide, i, 396

 coronado, ii, 274

 corpus vestiforme, i, 112

 corsair, ii, 430

 Corvula, ii, 355

 Corynolophus, i, 189; ii, 549
   figure of, i, 188
   luminous bulb in, i, 188

 Coryphæna, i, 210, 391
   figure of, ii, 287

 Coryphænidæ,
   family of, ii, 286

 Coryphænoides,
   figure of, i, 83; ii, 541
   leptocercal, tail of, i, 83

 Coryphopterus, ii, 462

 Corythroichthys, ii, 236

 Costa, i, 412

 Cottidæ, i, 208, 290; ii, 363, 442, 449, 453, 455, 501, 504, 525
   family of, i, 441
   fossil forms, i, 449

 Cottocomephorus, ii, 525

 Cottogaster, i, 300

 Cottunculus, i, 219; ii, 441, 447, 449

 Cottus, i, 169, 219, 312, 391; ii, 443, 445, 449
   figure of, ii, 444, 445, 446

 Couch, i, 410
   on fighting-fish, i, 165
   on skippers, ii, 21

 Coues,
   on classification, i, 368
   on meaning of species, i, 379
   on synonymy, i, 374

 cowfish,
   figure of, i, 373; ii, 416
   skeleton of figured, i, 215; ii, 418

 cow's tongue, ii, 497

 crab-eater, ii, 282

 Cragin, i, 171

 craig-fluke, ii, 494

 Cramer, i, 408, 420, 422

 cramp-fishes, i, 554

 cranial nerves,
   figure of, i, 111

 Craniomi,
   suborder of, ii, 456

 Craniotes, i, 588

 cranium,
   bones of, i, 36-39
   inferior view, i, 38
   lateral view, i, 36
   posterior view, i, 40
   of Roccus, figured, i, 36-39
   of Sebastolobus, i, 53
   superior view, i, 37

 crappie, ii, 168, 297
   figure of, ii, 297
   photograph of, ii, 298

 Cratinus, i, 271

 cravo, ii, 244

 crawl-a-bottom, ii, 312

 crayfish, ii, 147

 creek fish,
   figure of, i, 315; ii, 172

 Crenilabrus, i, 207, 260, 267; ii, 387

 creole-fish, ii, 328, 329

 Crescent lake trout, ii, 101

 Cricodus, i, 603

 Cristiceps, i, 208; ii, 508, 513

 Cristivomer, i, 291; ii, 62, 115
   figure of, ii, 114

 croaker, ii, 353, 355

 Cromeriidæ, ii, 56

 cross-bow shooter, ii, 413

 Crossognathidæ, ii, 215, 521
   family of, ii, 224

 Crossopholis, ii, 21

 Crossopterygians, i, 78, 79, 89, 91, 204, 436, 457, 511-515, 591, 602,
    623, 624; ii, 38
   figure of, i, 451
   fins of, i, 601

 Crossopterygii, i, 382, 462, 599, 600, 601, 608

 crustacean parasites, i, 340

 Cryptacanthididæ, ii, 516

 Cryptacanthodes,
   figure of, i, 516

 Cryptocentrus, i, 264; ii, 462

 Cryptopsaras,
   figure of, ii, 547

 Cryptotomus,
   figure of, ii, 391

 crystal darter,
   figure of, ii, 313

 crystal goby, ii, 466

 Crystallias,
   figure of, i, 218; ii, 454

 Crystallogobius, ii, 466

 Ctenochætus, ii, 409

 Ctenodentex, ii, 340

 Ctenodipterini,
   order of, i, 612

 Ctenodontidæ, i, 613

 Ctenodus, i, 613

 ctenoid scales, i, 20, 21; ii, 39

 Ctenoidei, ii, 39, 209

 Ctenolabrus, ii, 387

 Ctenolates, ii, 320

 Ctenoptychius, i, 555

 Ctenothrissa,
   figure of, ii, 48

 Ctenothrissidæ,
   figure of, ii, 48

 cuatro ojos, ii, 194

 Cuban fishes, i, 314

 cubero, ii, 335

 cuboid, i, 19

 cub-shark,
   figure of, i, 542

 cuckold, ii, 417
   figure of, i, 373; ii, 416

 cucugo, ii, 413

 cultus cod, ii, 442
   figure of, ii, 440

 Cunias, i, 541

 cunner, ii, 387

 Cunningham,
   on eye of flounder, i, 176

 Curimatus, ii, 162

 cusk-eel, i, 187, 314; ii, 539
   figure of, ii, 520

 cutlass-fishes, i, 149, 210; ii, 267
   figure of, ii, 268
   species of, ii, 472

 cutthroat trout, ii, 95-97, 102, 104, 106

 Cuvier, i, 103, 105, 400, 404, 428; ii, 39, 307
   Günther on, i, 400
   Lyman on, i, 401
   portrait of, i, 399

 Cycleptus, ii, 173

 Cycliæ, i, 204, 437, 462, 592, 593
   subclass of, i, 591

 Cyclobatis, i, 557

 Cycloganoidei, ii, 34

 cycloid scales, i, 20, 22; ii, 39

 Cycloidei, ii, 39

 Cyclopterichthys, ii, 454

 Cyclopteridæ, i, 198, 208
   family of, ii, 453

 Cyclopterus, i, 391; ii, 453, 455
   figure of, i, 220; ii, 454

 Cyclospondyli, i, 510, 543
   order of, i, 545

 cyclospondylous, i, 49

 cyclospondylous sharks, i, 549

 Cyclostomata, i, 593

 Cyclostomes, i, 113, 443, 486-505, 570, 596, 592, 617
   extinct forms, i, 487

 Cyclostomi, i, 462, 584

 Cyclothone, ii, 129

 Cyclurus, ii, 36

 Cymatogaster, ii, 376
   figure of, i, 125; ii, 372

 Cymolutes, ii, 390

 Cymothoa, i, 340

 Cynoglossinæ, ii, 497

 Cynoglossus, ii, 497

 Cynoscion, i, 94, 324; ii, 107
   figure of, ii, 353

 Cynthia,
   figure of, i, 476

 Cynthiidæ, i, 475

 Cyprinidæ, i, 33, 46, 205, 230, 251, 285, 287, 290, 406; ii, 65, 161,
    162, 164-171
   fossil forms, ii, 174
   species of, ii, 165

 Cyprinodon, ii, 198, 201
   figure of, ii, 196

 Cyprinodontes, ii, 194

 Cyprinodontidæ, i, 290

 Cyprinus, i, 391; ii, 170, 174

 Cypselurus, ii, 213
   figure of, i, 157, 440

 Cyrthaspis, i, 575

 Cyttoides, ii, 249

 Cyttus, ii, 249


 dabonawa, i, 430

 dace, i, 251; ii, 118, 162, 166, 168

 Dactylagnus, ii, 506

 Dactyloscopidæ, ii, 506

 Dactyloscopus, ii, 506

 daddy sculpin, ii, 445

 Dalatias, i, 546

 Dalatiidæ, i, 548

 Daldorf,
   on capture of Anabas, i, 163
   on climbing-fish, ii, 367

 Dale, ii, 539

 Dallia, i, 51
   figure of, i, 149; ii, 206

 Dalliidæ, i, 290; ii, 206

 Damalichthys,
   figure of, ii, 374

 damsel-fish, ii, 381
   figure of, ii, 382

 Dapediidæ, ii, 25

 Dapedium,
   figure of, ii, 25

 Dapedoglossus, ii, 56

 darters, i, 209, 231, 300, 304; ii, 166, 306, 310-315

 darter goby,
   figure of, ii, 462

 Darwin, i, 408
   on noises of catfish, i, 168

 daruma-okose, ii, 436

 Dasyatidæ,
   family of, i, 555

 Dasyatis,
   figure of, i, 247, 556

 Dasyscopelus, ii, 133

 Davis, H. S., ii, 81, 84
   on chinook salmon, ii, 85

 Davis, J. W., i, 426
   on fossil teeth, i, 525

 Dawson, i, 427, 594

 Day, i, 416; ii, 90, 92, 95
   on calling fishes, i, 168
   on electric eel, i, 170
   on grayling, ii, 121
   on Labyrinthici, ii, 365
   on sole, ii, 496, 497

 day chub,
   head of, figured, ii, 167

 dealfish, ii, 477, 480
   figure of, ii, 478

 Dean, i, 512, 591, 594, 595
   on Acanthodei, i, 517, 518
   on Arthrodira, i, 518, 588
   on Chimæras, i, 563
   on fin migration, i, 75
   on fossil forms, i, 422
   on lateral line, i, 23
   on lung-fish, i, 618
   on Ostracophores, i, 571
   portrait of, i, 417
   on sharks, i, 511, 531
   on Teleosts, i, 135

 Deania, i, 546

 deathfish, i, 183

 Death Valley fish,
   figure of, ii, 199

 Decapterus, ii, 274

 decurrent flounder,
   figure of, i, 441

 deep-sea angler,
   figure of, ii, 548

 deep-sea Chimæra,
   figure of, i, 449

 deep-sea fishes, i, 246, 247, 408; ii, 129

 degenerate fishes, i, 210, 211, 216, 218

 degeneration,
   of eye, i, 220
   in fishes, i, 54
   in lamprey, i, 217
   of structure, i, 216
   in tunicates, i, 480

 Delaroche, i, 95

 Dekay, i, 418

 Delfin,
   on hagfishes, i, 489

 Deltistes, ii, 172

 Deltodus, i, 531

 Dendrodus, i, 603

 dentary, i, 606

 Dentex, i, 94; ii, 338, 340

 Dercetes, ii, 136

 Dercetidæ, ii, 136, 137, 158

 Derepodichthyidæ, ii, 520

 Derichthyidæ, ii, 155

 Derichthys, ii, 153
   figure of, ii, 156

 Dermopteri, i, 486

 Desmarest, i, 396

 development, i, 217
   of bony fishes, i, 135
   Dean on, i, 135
   embryonic, i, 133
   of flounders, i, 144
   heredity in, i, 134
   of horsehead-fish, i, 148
   of paired fins, i, 66

 devil ray,
   figure of, i, 559

 De Vis, i, 416

 Devonian,
   fishes, i, 436
   lamprey, i, 563
   sharks from, i, 65

 Diabasis, i, 375

 diablo, ii, 552

 Dialarchus, ii, 448

 Dialommus, i, 117

 diamond,
   fishes, ii, 398
   flounder, ii, 493
   snapper, ii, 337

 Diaphus, ii, 133
   figure of, ii, 132

 Dibothrium, 345
   figure of, ii, 103

 Dibranchus, i, 207; ii, 552

 Dicentrodus, i, 522

 Dicentrarchus, i, 324; ii, 321, 330

 dichotomous rays, i, 596

 Dicranodus, i, 521

 Dictyorhabdidæ, i, 565

 Dictyorhabdus, i, 435, 565, 578

 Dictyopyge, ii, 16

 Dictyopygidæ, ii, 14

 Dictyosoma, 512

 Didemnidæ, i, 477

 Didymaspis, i, 576

 Didymodus, i, 521, 525

 Dinematichthys, ii, 524

 Dinichthyidæ, i, 587

 Dinichthys, i, 587, 589
   figure of, i, 445, 584
   jaws of figured, i, 583

 Diodon, i, 273, 393, 394
   figure of, i, 17; ii, 422

 Diodontidæ,
   family of, ii, 422

 diœcious fishes, i, 124

 diphycercal tail, i, 49, 81, 83, 84, 507, 513, 516, 598
   Boulenger on, i, 84
   Dollo on, i, 84

 Diplacanthidæ, i, 517, 518

 Diplacanthus,
   figure of, i, 517

 Diplectrum, ii, 329

 Diplesion,
   figure of, i, 247; ii, 312

 Diplodus, ii, 347
   figure of, ii, 346

 Diplognathus, i, 584, 589

 Diplomystes, ii, 178

 Diplomystidæ, ii, 178

 Diplomystus,
   figure of, i, 205, 453; ii, 52

 Diploneumoni, i, 612, 619

 Diploprion, ii, 327

 Diplopterus, i, 82, 604

 Diplospondyli, i, 509, 523

 Diplurus, i, 605

 Dipneusti, i, 405, 462, 582, 599, 601, 605, 607, 622, 624; ii, 4
   relationship of, i, 609, 610
   subclass of, i, 609-622

 Dipnoans, i, 436, 512, 572, 582, 583; ii, 3, 8
   air-bladder in, i, 101
   classification of, i, 612
   ear sac in, i, 120
   figure of, i, 449
   pectoral fin in, i, 60
   shoulder-girdle in, i, 86, 88

 Dipnoi, i, 77, 85, 89, 382

 Diptera, ii, 306

 Dipteridæ, i, 612

 Dipterus, i, 612
   figure of, i, 437, 449

 Discobatis, i, 553

 Discocephali, ii, 459-480
   Gill on, ii, 470
   suborder of, ii, 468

 diseases of fishes, i, 340-358
   contagious, i, 340
   parasitic, i, 342
   remedies for, i, 342

 Dismal Swamp fish,
   figure of, i, 116; ii, 201

 dispersion of fishes,
   Agassiz on, i, 284
   barriers to, i, 297, 310, 311
   causes of, i, 318
   Cope on, i, 286
   by floods, i, 301
   of fresh-water fishes, 282-296
   of river fishes, 297-319

 dissection of the fish, i, 26-33

 Distomidæ, i, 477

 distribution of fishes,
   affected by coast line, i, 247, 261
   agency of currents in, i, 242
   centers of, i, 243
   determined by temperature, i, 241
   of fresh-water forms, i, 249
   general laws of, i, 238
   of marine forms, i, 245
   Panama, barrier to, i, 266
   of shore fishes, i, 263-265
   Suez, barrier to, i, 266
   zones of, i, 249, 251, 252

 Ditrema, ii, 375

 Dittodus, i, 521, 525

 doctor-fish, ii, 408

 Döderlein, i, 411, 416

 dogfishes, i, 519
   figure of, i, 545

 dogoro, ii, 381

 dog salmon, ii, 71-73, 80, 81

 dog snapper, ii, 336

 Dolichoglossus, i, 463

 Doliolum, i, 479

 dollar-fish, ii, 283

 Dollo, i, 415, 427, 600, 601; ii, 502
   portrait of, i, 413
   on tail forms, i, 84

 Dolloa, ii, 541

 Dolly Varden trout, i, 305; ii, 112, 113
   figure of, i, 327; ii, 114

 dolphins, i, 210; ii, 286, 362
   figure of, ii, 287

 Doncella,
   figure of, i, 297; ii, 180, 396

 Donovan, i, 410

 dorados, ii, 286
   figure of, ii, 287

 Doras, ii, 183

 Doratonotus, ii, 388

 Dormeur,
   figure of, ii, 460

 Dormitator,
   figure of, ii, 461

 dorsal fin, i, 10, 603
   figured, i, 49

 Dorosoma, i, 32, 300
   figure of, ii, 53

 Dorosomatidæ, ii, 53

 Dorosomidæ, i, 290

 Doryichthys, ii, 236

 Dorypteridæ, ii, 14-16

 Dorypterus, ii, 15, 16

 Draciscus,
   figure of, ii, 452

 Draconetta, ii, 506

 Draconettidæ, ii, 506

 dragonets, i, 246; ii, 504

 drawing net at Milo,
   photograph of, i, 281

 Drepane, ii, 401

 Drepanaspidæ, i, 574

 Drepanaspis, i, 570
   figure of, i, 574

 Drepanidæ, ii, 401

 Drepaniodus, i, 488

 drum, i, 290
   figure of, ii, 358

 duck-billed eels, ii, 150, 151

 Ductor, ii, 278

 ducts, i, 28

 ductus cholidechus, i, 32

 Dufosse,
   on air-bladder, i, 97

 Dugès, i, 90, 420

 Dugunonutatatori, ii, 472

 Duméril, i, 398, 401

 duodenum, i, 32

 Dussumieriidæ, ii, 52

 Dussumieria, ii, 52

 Duverncy, i, 390

 Duymæria, i, 260; ii, 390

 dwarf,
   herring, ii, 54
   perch, ii, 306
   salmon, ii, 117
   sunfish, ii, 467

 Dybowsky, i, 411

 Dynatobatis, i, 553

 Dysommidæ, ii, 150

 Dytiscus, ii, 144


 eagle ray,
   figure of, i, 558

 early writers on fishes, i, 272, 422, 423

 earliest sharks, i, 436, 443

 ear of fish, i, 119-121

 ear sac, i, 119, 120

 ear stones, i, 119

 earthquakes,
   fatal to fishes, i, 356; ii, 137

 Eastman, i, 427, 428
   on Cestraciont shark, i, 529
   on Clastes, ii, 32
   on Neoceratodus, i, 619
   portrait of, i, 425
   on teeth of Edestus, i, 530

 Ebisu, the god of fishes, ii, 344
   figure of, ii, 343

 Ebisus, ii, 323

 Echeneididæ, ii, 468, 470

 Echeneis, i, 391; ii, 468, 470, 471

 Echidna, i, 211; ii, 152, 153

 Echidnocephalus, ii, 138

 Echinorhinidæ,
   family of, i, 547

 Echinorhinus, i, 547

 Echiodon, i, 84

 economic fishes, i, 333

 ectoblast, i, 152

 ectocoracoid, i, 87

 ectoderm, i, 139

 ectopterygoid, i, 606

 Edaphodon, i, 565

 Edestus,
   teeth of, figured, i, 529

 eel-back flounder,
   figure of, ii, 494

 eel-fairs, ii, 142

 eel-like fishes, ii, 137-158

 eel-mother, ii, 144

 eel-pouts,
   figure of, ii, 518, 519

 eels, i, 21, 210, 217, 268, 290; ii, 40, 44, 147, 153, 157
   Cope on, ii, 139
   Günther on, ii, 141
   larva of, figured, ii, 148
   migration of, ii, 142
   reproduction of, ii, 143
   species of, ii, 148
   shoulder-girdle in, ii, 142
   Woodward on, ii, 140

 effects on distribution,
   of shore line, i, 262
   of temperature, i, 149

 Egerton, i, 423

 Egertonia, ii, 396

 eggs of fish,
   artificial impregnation of, i, 150
   of bottle-nosed chimæra, i, 127
   care of, i, 128
   carrying of, i, 128, 171
   of Embiotocidæ, i, 127
   embryo of, i, 128
   fertilization of, i, 125
   figures of, i, 127
   germ disk in, i, 135
   hatching of, i, 125
   of herring, i, 125
   month incubation of, i, 170, 171
   transportation of, i, 171

 Eichwald, i, 411, 427

 Eigenmann, i, 415, 420; ii, 147, 148, 376
   on blind fishes, i, 117, 221, 222; ii, 202, 523
   on Nematognathi, ii, 178
   photograph by, i, 222
   portrait of, i, 417

 Eigenmannia, ii, 187

 eighteen-spined sculpin,
   figure of, ii, 447

 Ekström, i, 410

 Elacate, ii, 282, 470, 471

 Elagatis, ii, 274

 Elanura,
   figure of, ii, 444

 Elasmobranchiates, i, 384

 Elasmobranchii, i, 462, 507, 584; ii, 7

 Elasmobranchs, i, 92, 102, 204, 506-522, 571, 583, 588, 589
   characters of, i, 506-508
   classification of, i, 507-510
   ear sac in, i, 120
   geological distribution of, i, 459
   notochord in, i, 57
   subclass of, i, 507

 Elassoma, i, 290; ii, 296, 307, 467
   figure of, ii, 295

 Elassomidæ, i, 290; ii, 296
   family of, ii, 295

 elastic spring, i, 96

 Elater, i, 582

 electric catfish,
   figure of, ii, 183

 electric cells, i, 553

 electric eel, i, 186; ii, 140
   Day on, i, 170

 electric organs, i, 25, 186, 187

 electrophores, ii, 187, 188

 Electrophoridæ, ii, 187

 Electrophorus, i, 170, 186

 Eleotrids, ii, 460

 Eleotris, i, 254
   figure of, ii, 460

 Elera, i, 414

 Eleginus, ii, 537

 elephant sharks, i, 540
   figure of, i, 565

 Elliott,
   on trout, ii, 105

 Elonichthys, ii, 14

 Elopidæ, i, 43; ii, 35, 41-44

 Elopopsis, ii, 43

 Elops, i, 205, 393; ii, 43, 221
   figure of, i, 454; ii, 42

 Embiotoca, i, 404

 Embiotocidæ, i, 207, 290; ii, 373
   Agassiz on, i, 377-379
   anal fin in, i, 125
   viviparity of, i, 376, 377

 Emblemaria,
   figure of, ii, 510

 embryo, i, 136, 138, 139

 embryology and growth, i, 131-151

 Embolichthys, ii, 522
   figure of, ii, 521

 emerald-fish, ii, 462

 Emery, i, 412; ii, 480, 481

 Emmelichthys, i, 262; ii, 346, 347

 Emmydrichthys,
   figure of, i, 180; ii, 436

 Empetrichthys,
   figure of, ii, 199

 Empo, ii, 137

 Enantioliparis, ii, 455

 Enchelurus, ii, 138

 Enchelycephali, ii, 140, 141, 147, 152
   suborder of, ii, 142

 Enchelynassa, ii, 153

 Enchelyopus,
   figure of, ii, 539

 Enchodontidæ, ii, 136, 137

 Enchodus, ii, 136

 Endoskeleton, i, 439

 Enedrias, ii, 512

 Engraulididæ, ii, 54

 Engraulis, i, 205; ii, 54

 Enneacanthus, ii, 301

 Enophrys,
   figure of, ii, 443

 Enoplosidæ, ii, 317

 Enoplosus, i, 268; ii, 317

 Enteropneusta, i, 457, 461, 462
   classification of, i, 464

 entoderm, i, 138

 Entosphenus, i, 490

 entozoa, i, 348

 Eocottus, ii, 449

 Eomyrus, ii, 150

 Eopsetta, i, 205; 491

 Eothynnus, ii, 266

 Epelasmia, ii, 397, 398

 Eperlanus, ii, 123

 Ephippidæ, ii, 400

 Ephippus, i, 268; ii, 400

 epiblast, ii, 5

 Epigonichthys, i, 483

 Epigonus, ii, 317

 Epinephelus, i, 19; ii, 323, 330
   figure of, i, 20; ii, 324-326, 328

 Epiphysis, i, 112
   figure of, i, 111

 Eptatretidæ, i, 489

 Eptatretus, i, 490
   figure of, i, 198

 equatorial fishes,
   specialization of, i, 248

 equatorial zone, i, 251

 Eques, ii, 357

 Equula, ii, 287

 Erebus, i, 408

 Ereunias,
   figure of, ii, 450

 Ereuniidæ, ii, 449

 Ericymba,
   figure of, ii, 165

 Erimyzon, i, 292; ii, 175
   figure of, i, 315; ii, 172

 Eriptychius, i, 435, 603, 578

 Erisichthe, ii, 34

 Erismatopteridæ, ii, 242, 296

 Erismatopterus, ii, 243
   figure of, ii, 242

 Ernogrammus, ii, 513

 Erosa, ii, 436

 Erpetichthys, i, 204

 Erpetoichthys, i, 450
   figure of, i, 608

 Erpichthys, i, 608; ii, 510

 Erythrichthys, ii, 347

 Erythrinidæ, ii, 162

 Erythrinus, ii, 160

 escolars, ii, 267, 317

 Esmarck, i, 410

 Esmeralda, ii, 462

 esmeralda de mar,
   figure of, ii, 461

 Esocidæ, i, 290; ii, 190, 192

 Esox, i, 109, 253, 315, 327, 391; ii, 190, 194
   figure of, i, 328; ii, 192

 Etelis, i, 262; ii, 338
   figure of, ii, 337

 Etheostoma, i, 129, 283; ii, 310, 315
   figure of, i, 231; ii, 314

 Etheostominæ, i, 230, 232; ii, 166, 306, 307, 310

 ethmoid, ii, 142

 Etmopterus,
   figure of, i, 189, 546

 etrumei-iwashi, ii, 52

 Etrumeus, ii, 52

 Eucalia, ii, 232

 Eucitharus,
   figure of, ii, 488

 Eucinostomus, ii, 347

 Eugnathidæ, ii, 26

 eulachon, i, 321; ii, 19, 125, 126
   figure of, i, 320; ii, 124

 Euleptorhamphus, ii, 212

 Eumicrotremus, ii, 135

 Euphaneropidæ, i, 576

 Euphrosen, i, 396

 Eupomotis, i, 283
   figure of, i, 7, 13; ii, 301

 European chub,
   pharyngeals of, i, 48
   teeth of, figured, ii, 164

 European lancelet,
   figure of, i, 120

 European sculpin,
   figure of, i, 219

 European soles, ii, 496

 Eurylepis, ii, 14

 Eurynotus,
   figure of, ii, 15

 Eurypharyngidæ, ii, 156

 Eurypharynx, ii, 156

 Eurypholis,
   figure of, ii, 136, 137

 Euselachii, i, 532

 Eusthenopteron, i, 603

 Eutæniichthys,
   figure of, ii, 467

 Euthynotus, ii, 34

 Evenchelys, ii, 153

 Eventognathi, i, 405; ii, 160, 162

 everglade minnow,
   figure of, ii, 197

 everglade pigmy perch,
   figure of, ii, 295

 Evermann, ii, 69, 100, 103, 354
   on Panama fishes, i, 274
   portrait of, i, 421
   on Two Ocean Pass, i, 307-310

 Evermannellidæ, ii, 135

 Evermannella, ii, 136

 Eviota, ii, 460, 467

 evolution of fishes, i, 223-225, 435-459
   Dean on, i, 223

 Exerpes,
   figure of, i, 276; ii, 511

 Exocœtidæ, ii, 210, 211, 214

 Exocœtoididæ, ii, 134

 Exocœtoides, ii, 133

 Exocœtus, i, 391; ii, 213

 Exoglossum,
   head of, figured, ii, 167

 Exonautes, ii, 213

 exoskeleton, i, 20

 Exostoma, ii, 184

 extension of Indian fauna, i, 267

 exterior of fish, i, 16-25

 external gills,
   figure of, i, 78, 602
   Kerr on, i, 76
   Mauer on, i, 77
   Orr on, i, 77
   Rusconi on, i, 77

 extinction of species, i, 240
   causes of, i, 241

 Eyclesheimer, i, 428

 Eydoux, i, 408

 eye of fish, i, 119

 eye of flounder,
   in larval stage, i, 174
   migration of, i, 173-176
   Williams on, i, 174-178

 eye-of-the-sea, ii, 361


 Faber, i, 396

 Fabricius, i, 394

 Facciola, i, 412

 factors of extinction, i, 442

 fading of pigment in spirits, i, 235

 fair maid, ii, 344

 fallfish, i, 311; ii, 167

 fall-salmon, ii, 80

 family,
   definition of, i, 373

 fan-tailed darter, ii, 315

 Farquhar,
   on Opah, ii, 244

 fat cod, ii, 440

 fat head, ii, 388

 fatherlasher, ii, 445

 faunal areas,
   minor, i, 248
   of Japanese fishes, i, 257

 faunal resemblances, i, 259, 260

 faunal differences, i, 260, 261

 favorable waters have most species, i, 301

 fear in fishes, i, 163
   expressions of, i, 165

 Felichthys,
   figure of, ii, 179

 fiatola, ii, 283

 Fierasfer, i, 84; ii, 520
   figure of, i, 159; ii, 522, 523

 Fierasferidæ, ii, 158, 522

 fighting-fish, ii, 370
   of Siam, i, 163

 filefish, ii, 413-415
   figure of, i, 182

 filiform, i, 19

 Filippi, i, 412

 finfold, i, 63, 64
   Balfour's theory of, i, 69

 fin migration,
   Dean on, i, 75
   of Heterodontus, i, 75

 finnan haddie, ii, 537

 fins of fishes,
   described, i, 9, 10, 20, 24, 25
   migration of, i, 75
   morphology of, i, 62-90
   origin of, i, 62

 fin-spines, i, 528, 529; ii, 39
   of Hybodus, i, 528, 529
   of Onchus, figured, i, 509

 Fischer,
   on fishes of Panama, i, 275

 Fish Commission,
   fish stocking by, i, 346

 fisheries,
   economic, i, 337
   salmon, i, 81, 87

 fishes,
   in action, i, 11
   adaptation to environment, i, 156
   affection of, i, 167
   affected by temperature, i, 149
   age of, i, 144, 146
   air-bladder of, i, 12, 92, 93
   alimentary canal in, i, 31
   anadromous, i, 156, 160, 291
   anger of, i, 165
   in aquaria, i, 150, 165
   blood of, i, 11
   body form of, i, 16
   bones of, i, 10
   bony, i, 454, 506
   brain of, i, 12, 14, 109, 112
   breathing of, i, 5, 91, 103
   of British Museum, i, 402
   burrowing of, ii, 463, 465
   care of eggs by, i, 128
   catadromous, i, 162, 291
   catalogues of, i, 402
   channel, i, 291
   circulatory organs of, i, 26
   classification of, i, 367-386
   of Coal Measures, i, 223
   collecting of, i, 429
   color and coloration of, i, 6, 129, 226-236
   conditions of life of, i, 215
   of coral reefs, i, 235
   currents affecting, i, 243, 244
   deep sea, i, 408
   definition of, i, 3
   degeneration in, i, 54, 216, 218-220; ii, 547
   digestion and digestive organs of, i, 11, 26
   diœcious, i, 124
   dispersion of, i, 318
   diseases of, i, 340-358
   dissection of, i, 26, 27
   distortion in, i, 129
   distribution of, i, 237-255, 435
   domestication of, i, 149, 151
   ear of, i, 8, 119-121
   earliest forms of, i, 443
   eggs of, i, 125-135
   electric organs of, i, 25; ii, 187
   embryology of, i, 131-151
   evolution in, i, 223, 435-459
   exterior of, i, 16-25
   extinct, i, 224
   eye of, i, 6, 119
   eye-stalks of, ii, 466
   face of, i, 5
   fins of, i, 9, 10, 24
   flight of, i, 167
   flow of blood in, i, 107
   as food for man, i, 320-339
   food of, i, 11, 29
   form of, i, 4
   fossil, i, 422-428
   fresh-water, i, 250
   gall-bladder in, i, 26
   generalized forms of, i, 224
   gills of, i, 92
   growth of, i, 30, 144
   habits of, i, 152
   hearing of, i, 8, 119
   heart of, i, 11, 28, 106
   herbivorous, i, 30, 155; ii, 364
   hermaphrodite, i, 124
   homologies of bones in, i, 34
   hybridism in, i, 144
   instincts of, i, 154
   intestines of, i, 33
   intromittent organ in, i, 124
   with jugular fins, i, 456
   kidneys of, i, 11, 28
   killed by earthquakes, i, 356
   Labyrinthine, ii, 365
   larval forms, i, 142, 620, 621
   lateral line of, i, 9
   life cycle of, i, 3-5, 152
   lowland, i, 291
   luminous organs of, i, 188-190
   lungs of, i, 98
   measurements of, i, 19
   migration of, i, 160
   monstrosities among, i, 151
   mortality among, i, 357
   mountain, i, 291
   mouth of, i, 29
   muscles of, i, 25
   mythology of, i, 359
   naturalization of, i, 150
   nerves of, i, 12, 14, 109, 113; ii, 368
   nests and nest-building of, i, 15, 167, 128; ii, 184, 229-231
   noises of, i, 121, 168
   nostril of, i, 6
   nuptial colors in, i, 155, 156
   nutrition organs of, i, 29
   organs of,
     locomotion, i, 24
     phosphorescence, i, 194
     reproduction, i, 28, 124-130
     sense, i, 115-123
     sight, i, 6, 116
     smell, i, 115
     taste, i, 121
     touch, i, 122
   ovaries, i, 26
   oviparous, i, 125
   ovoviviparous, i, 125
   pain, sense of, in, i, 123
   parasites of, i, 340-344
   parasitic, i, 198
   pectoral limb of, i, 50
   pelagic, i, 156
   pineal eye in, i, 111
   poisonous, i, 180-185, 236; ii, 177, 411, 413, 421, 433,436, 526
   postembryonic development, i, 132
   posterior limbs of, i, 53
   preservation of, i, 431
   problem of highest, i, 383
   protection of young by, i, 128
   pugnacity of, i, 162
   recognition marks in, i, 7, 232, 236
   records of, i, 433
   scales of, i, 20
   sensitiveness to change, i, 150
   sexual modifications in, i, 129
   shoulder-girdle of, i, 50, 52
   skeleton of, i, 10, 214, 215
   specialization in, i, 219, 220, 224, 249; ii, 438
   spinal cord of, i, 112
   spineless, i, 25
   spiral valve in, i, 32
   tail of, i, 49
   teeth of, i, 5, 29
   tenacity of life in, i, 146, 147
   timidity of, i, 166
   tongue of, i, 6, 31
   upland, i, 291
   variety in tropics, i, 333
   viscera of, i, 26
   viviparous, i, 125; ii, 376
   voices of, i, 121
   where found, i, 158, 159
   zeoid, ii, 245

 fishes as food, i, 320-339

 fishes of Panama,
   Evermann on, i, 274
   Fischer on, i, 275
   Günther on, i, 272, 273
   Hill on, i, 277
   Upham on, i, 276
   Wright on, i, 275

 fish faunas,
   genera in, i, 262, 263
   Indian, i, 267
   of Japan, i, 255, 256, 259
   of Mediterranean, i, 259
   of Panama, i, 267
   separated by barriers, i, 255-281

 fish fighting, i, 162

 fish god of Japan,
   figure of, ii, 343

 fish guano, i, 538

 Fish-Hawk, the, i, 408; ii, 147

 fishing,
   apparatus for, i, 335
   for ayu, i, 333
   for tai, figured, i, 338
   with cormorants, i, 333, 335
   methods of, i, 334

 fishing-frog, i, 202; ii, 542
   capture of prey by, i, 169
   figure of, i, 18; ii, 545, 550

 fish-like vertebrates, i, 34

 fish of Paradise, ii, 369

 Fistularia, i, 85, 393; ii, 233, 390
   shoulder-girdle of, ii, 227

 Fistulariidæ, ii, 227
   family of, ii, 233

 Flammeo, ii, 254

 flashers, ii, 331

 flatfish family, i, 177; ii, 48

 flatheads, ii, 441

 Flesus, ii, 493

 Fleurieu's whirlpool, ii, 242

 flier, ii, 297

 flight of fishes, i, 157

 Floeberg, ii, 110

 Florida jewfish,
   figure of, ii, 323

 Florida lion-fish,
   figure of, ii, 433

 flounder, i, 117, 178, 203, 440; ii, 483-485, 488, 493, 494
   development of, i, 144
   diamond, ii, 493
   eel-back, ii, 493
   eyes of, i, 118, 174-178
   frog, ii, 493
   lantern, ii, 488
   larval form, i, 176; ii, 483, 484
   migration of eye, figured, ii, 484
   newly hatched, figured, i, 177
   osteology of, ii, 484
   peacock, ii, 488
   pole, ii, 494
   shoulder-girdle of, i, 58; ii, 2
   starry, ii, 493
   tail of, figured, ii, 486
   vertebræ in, i, 205
   wide-eyed, ii, 488
   wide-eyed, figured, i, 175
   young, figured, i, 175; ii, 482

 flower of the surf,
   figure of, ii, 218

 flow of blood in fish, i, 107

 flukes, ii, 494

 flying-fish, ii, 211-214
   figure of, i, 157, 341, 440
   parasites of, i, 342

 flyfish, ii, 429

 flying gurnard, ii, 456, 458
   figure of, i, 457

 flying robin, ii, 458

 Fodiator,
   figure of, ii, 213

 food-fishes,
   abundance of, i, 329
   relative rank of, i, 320

 food of lampreys, i, 491

 foolfishes, i, 206; ii, 413

 Foot-notes to Evolution,
   reference to, i, 302

 foramen, i, 92

 forelle, i, 327

 Forcipiger, ii, 404

 Forgy,
   on oarfish, ii, 473

 Forbes, i, 419
   on fish epidemics, i, 340

 formalin,
   as preservative, i, 432

 Forskål, i, 394

 Forster, i, 395

 fossil capelin, ii, 126, 127

 fossil darters, ii, 315

 fossil fishes, i, 205; ii, 48, 52, 53, 56, 174
   Agassiz on, i, 422, 423
   Dean on, i, 422
   earliest forms, i, 568
   figure of, i, 436, 454; ii, 47, 59
   first period of, i, 423
   from Green River, ii, 59
   morphological work on, i, 427
   second period, i, 424
   study of, i, 424
   third period, i, 427

 fossil gobies, ii, 467

 fossil herring,
   figure of, i, 453; ii, 52

 fossil trout, ii, 62, 118

 four-eyed fish,
   figure of, i, 117

 four-spined stickleback,
   figure of, ii, 232

 Fowler, i, 422

 fox shark, i, 536

 Frère Jacques, ii, 255

 fresh-water eels, ii, 149

 fresh-water fishes, i, 209; ii, 157, 160, 161
   dispersion of, i, 282-296
   distribution of, i, 249
   Günther on, i, 249
   of Japan, i, 256
   of North America, i, 290

 fresh-water minnows, i, 33

 fresh-water perch,
   figure of, ii, 373

 Friar Odoric,
   on fear in fishes, i, 166

 Fries, i, 410

 frilled shark, i, 361, 516
   figure of, i, 525

 Fritsch, i, 427, 428, 512

 frog,
   arm of, figured, i, 601

 frogfish, i, 197; ii, 549
   figure of, ii, 551

 frog flounder, ii, 493

 frostfish, ii, 537

 Fucus, ii, 512

 Fullarton, i, 177

 function of lateral line, i, 23

 Fundulus, ii, 194, 199
   figure of, i, 198

 fur seal,
   food of, ii, 127, 537


 Gadidæ, i, 290; ii, 522, 533

 Gadopsidæ, ii, 516

 Gadus, i, 209, 391
   figure of, i, 331; ii, 533

 Gazza, ii, 287

 gaff-topsail cat,
   figure of, ii, 179

 Gaidropsarus, i, 209; ii, 539

 Gaimard, i, 406

 galafata, ii, 413

 Galaxias, i, 223, 252, 253, 254
   Boulenger on, ii, 204, 205

 Galaxiidæ,
   family of, ii, 204

 Galei, i, 532

 Galeidæ, i, 540

 Galeichthys, i, 128, 242, 271, 273; ii, 178
   figure of, ii, 179

 Galeocerdo, i, 541, 542

 Galeoid sharks, i, 519

 Galeorhinidæ, i, 532, 540

 Galeorhinus, i, 454

 Galeus,
   figure of, i, 541

 gall-bladder, i, 26

 galliwasp, ii, 130

 galo, ii, 394

 Gambusia, i, 64, 66, 67; ii, 199

 Ganocephala, i, 85, 86

 Ganoidei, i, 444, 599, 616; ii, 2, 3, 13

 Ganoids, i, 22, 38, 88, 91, 139, 157, 159, 186, 204, 384, 569, 622; ii,
    1-36
   Agassiz on, ii, 9
   air-bladder in, i, 109
   classification of, ii, 13
   Gill on, ii, 9
   as a group, ii, 4, 9

 ganoid fish, i, 582
   figure of, i, 452, 453

 Garden, i, 390

 Garibaldi,
   figure of, i, 227; ii, 382

 garfish, ii, 147, 210, 211
   shoulder-girdle in, i, 59

 Garman, i, 405, 408, 420; ii, 183
   on blind fish, ii, 202
   on frilled shark, i, 525
   on Sunapee trout, ii, 109

 garpike, i, 290; ii, 30-32
   figure of, ii, 27
   fossil, ii, 32
   tail of, i, 82
   vertebræ of, i, 48

 garrupa, ii, 323

 gaspergou, ii, 354

 Gasteronemus, ii, 288
   figure of, ii, 289

 Gasterosteidæ, i, 128, 290
   family of, ii, 228, 232

 Gasterosteus, i, 161, 172, 391; ii, 229, 231, 236
   Lord on, ii, 230
   figure of, ii, 232

 Gastrostomus,
   figure of, ii, 156

 gastrula, i, 131, 132

 Gaudry,
   on leptocercal tail, i, 84

 Gay, i, 415

 Gegenbaur, i, 428, 511, 512, 591, 594, 601
   on archipterygium, i, 60
   on morphology, i, 68
   on pectoral fin, i, 67
   theory of, i, 73

 Gempylidæ,
   family of, ii, 267

 Gempylus, ii, 267

 general laws,
   of development, i, 133
   of distribution, i, 239

 generalization and specialization, i, 380

 genital organs, i, 124

 genus, i, 375
   definition of, i, 372

 Genyonemus, ii, 356

 Genypterus, ii, 520

 geographical distribution, i, 237-259
   of sharks, charted, i, 459

 geological evidence of submergence, i, 268

 Geophagus, ii, 381

 Geotria, i, 491

 Gephyrura, ii, 201

 Gephyroberyx, ii, 252

 gephyrocercal tail, i, 84, 604
   figure of, i, 85

 German carp, ii, 175

 germ-cells, i, 124

 Germo, 210; ii, 262, 266
   figure of, ii, 263

 Gerres, i, 271, 273
   figure of, ii, 349

 Gerridæ, i, 206; ii, 372
   family of, ii, 347

 Gervais, i, 408

 ghost-fishes, ii, 150, 516

 giant bass, ii, 324

 Gibbes, i, 426

 Gibbons, i, 419
   on Embiotocidæ, ii, 377

 Gibbonsia,
   figure of, ii, 508

 gibbus, ii, 45

 Gigactinidæ, ii, 551

 Giglioli, i, 412

 Gila, i, 304; ii, 169

 Gilbert, i, 408, 415, 420; ii, 239
   on Astroscopus, i, 187
   on coracoid plate, ii, 206
   on flight of fishes, i, 157
   on island forms, i, 240
   on larval forms, i, 142
   portrait of, i, 421

 Gilbertidia, ii, 441, 447, 449
   figure of, ii, 451

 Gill, i, 408, 419, 448, 528, 591, 594, 600; ii, 24, 34, 40, 52, 317,
    365, 366, 502, 511
   on anglers, ii, 543
   on Discocephali, ii, 470, 471
   on eels, ii, 143, 156
   on high and low forms, i, 383
   on work of Lacépède, i, 398
   on New Zealand fauna, i, 252
   on paired limbs, i, 85
   portrait of, i, 407
   on Selachii, i, 509
   on shoulder-girdle, i, 86-89
   sketch of, i, 405
   on soles, ii, 496
   on swallowers, ii, 360, 361
   on tilefish, ii, 361, 362

 gill,
   arches, i, 45, 91, 508
   basket, figured, i, 92, 485
   covers, i, 44
   filaments, i, 107
   offices of, i, 11
   openings, i, 91
   rakers, i, 31, 46
   septum, i, 73
   slits, i, 508

 Gillellus, ii, 506

 Gillichthys, ii, 462
   figure of, ii, 463

 Gillicus, ii, 48

 Ginglymodi, ii, 24, 30

 Ginglymostoma, i, 533

 Ginglymostomidæ, i, 533

 Girard, i, 405, 419; ii, 378, 379

 girdle in Dipnoans, i, 86

 Girella, ii, 348

 gisu, ii, 46

 gizzard-shad, i, 290; ii, 51, 53

 glacial epoch,
   effect on dispersion, i, 316

 Glaucosoma, ii, 323, 340

 Glandiceps, i, 465

 Glanencheli, ii, 187

 glassy darter, ii, 313

 glenoid, i, 90

 Glesnæs oarfish, ii, 472
   figure of, i, 363

 globefishes, i, 197, 440, 455; ii, 419
   figure of, i, 244; ii, 422

 Globulodus, ii, 15

 Glossobalanus,
   figure of, i, 464
   larva of, figured, i, 463

 glut-herring, ii, 50

 Glyphisodon, i, 267
   figure of, ii, 383

 Glyptocephalus, i, 206; ii, 494

 Glyptolepis, i, 603

 Glyptopomus, i, 604

 Gmelin, i, 395, 397

 Gnathanacanthidæ, ii, 514

 Gnathodentex, ii, 341

 Gnathonemus,
   figure of, ii, 189

 Gnathostomata, i, 78

 Gnathostomes, i, 35, 572, 573

 Gnathostomi, i, 508, 570

 Gnathypops,
   figure of, ii, 359

 goatfish, i, 198; ii, 351, 379
   figure of, i, 122

 gobies, i, 428; ii, 459

 Gobiesox, ii, 529, 530, 531

 Gobiidæ, i, 22, 206, 290; ii, 306
   family of, ii, 459

 Gobius, i, 208, 273, 391; ii, 461, 467

 Gobio, ii, 167, 175

 Gobioides, ii, 467

 Gobioidea, ii, 470

 Gobioidei, 11, 459-480
   suborder of, ii, 459

 Gobiomorus,
   figure of, i, 160

 Gobionellus, i, 208
   figure of, ii, 461

 Gobiosoma, i, 313; ii, 462

 goblin sharks,
   figures of, i, 535

 goby, i, 290; ii, 462, 466

 gofu, ii, 434
   figure of, i, 229

 goggler, ii, 275

 golden,
   shiner, ii, 167
   goldsinny, ii, 387
   surmullet,
     figure of, i, 322; ii, 352
   trout, ii, 99

 goldfish, ii, 170, 171
   of Japan, i, 151

 Gomphosus, ii, 390

 Goniistius, ii, 363

 Goniognathus, ii, 287

 Gonioplectrus, ii, 323

 Gonorhynchidæ, ii, 54-56

 Gonorhynchus, ii, 56

 Gonostoma, ii, 129

 Gonostomidæ, ii, 129

 Gonzalez, i, 414

 Goodea, ii, 199, 201
   figure of, i, 126; ii, 200
   with young, figured, i, 126

 Goodsira, i, 476

 goody, ii, 356

 goosefish, ii, 545

 Gorbuscha, ii, 73

 Goode, i, 408, 419; ii, 307, 308
   on albacore, ii, 267
   on American fisheries, i, 335
   on codfish, ii, 534
   estimate of herring product, i, 330
   on fishing-frog, ii, 545
   on habits of mullets, ii, 219, 220
   on mackerel, ii, 260, 264, 265
   on menhaden, ii, 51
   portrait of, i, 407
   on swordfish, ii, 270

 Gordiichthys, i, 211; ii, 153

 Gordius, ii, 143, 144

 Gosfordia, i, 613

 Gosse, i, 415

 Gouan, i, 397

 gatasami, ii, 361

 Gottsche, i, 428

 goujon, ii, 182

 gourami, ii, 369

 gouramy,
   nest of, i, 167

 Grammicolepidæ,
   family of, ii, 249

 Grammicolepis, ii, 249

 Grammistes, ii, 330

 grande écaille,
   figure of, ii, 43

 Granodus, i, 565

 Grantea, ii, 544

 Graphiurus, i, 605

 Grassi, i, 428

 grass rockfish, ii, 429

 Gray, i, 416

 grayling, i, 150, 305; ii, 120-138

 gray snapper, ii, 335
   figure of, ii, 334

 Great Basin,
   chub of, i, 287
   dispersion of fishes in, i, 316
   fishes of, i, 302

 great blue cat, ii, 180

 great oarfish, ii, 472

 Greeley, i, 422

 Green,
   on Sacramento perch, i, 179

 green-backed trout, ii, 104
   figure of, ii, 105

 green cod, ii, 537

 Greene,
   on Porichthys, i, 190-197; ii, 526

 greenfish, ii, 348

 Greenland char, ii, 109

 Greenland halibut, ii, 491

 Greenland shark, i, 547

 greenling, ii, 439
   figure of, ii, 440

 green mackerel,
   figure of, ii, 275

 Green River shales, i, 205; ii, 52, 57-59

 green rockfish, ii, 429

 green-sided darter,
   figure of, i, 247; ii, 312

 green wrasse, ii, 387

 Gregarinidia, i, 242

 grenadier, i, 84; ii, 540
   figure of, ii, 541

 grilse, ii, 91

 grindle, ii, 35

 griset,
   figure of, i, 523

 Gronias, ii, 181

 Gronovius, i, 390

 groupers, ii, 323

 grubby, ii, 446

 grunt, i, 239
   figure of, ii, 340

 grunters, ii, 340

 gruntfishes, i, 121

 Grystes, i, 302

 Guacamaia, ii, 394
   figure of, i, 330

 guahu, ii, 266

 guasa, ii, 323

 guavina de rio, ii, 459
   figure of, ii, 460

 Guaymas,
   fishes of, i, 274

 gudgeon, i, 122; ii, 167

 Guichenot, i, 412, 415

 guipo, ii, 512

 guitar-fishes, i, 550
   figure of, i, 551

 gular plate, i, 43; ii, 33

 Güldenstadt, i, 395

 Gulf Stream, i, 239
   deep-sea fish of, i, 276

 gulper-eel, ii, 156

 gulpers, ii, 155

 gunnel,
   figure of, ii, 512

 Gunner, i, 396; ii, 245

 Günther, i, 88, 255, 259, 404; ii, 3, 95, 135, 161, 183, 229, 371
   on archipterygium, i, 60
   on Barramunda, i, 615
   catalogue of, i, 402
   on work of Cuvier, i, 400
   on deep-sea fishes, ii, 136
   on dispersion, i, 289
   on eels, ii, 141
   on electrophores, ii, 188
   estimate of eggs by, i, 128
   on fishes of Panama, i, 272, 273
   on Lepidosteus, ii, 5
   on month gestation, i, 173
   on pain in fishes, i, 123
   on poison glands, i, 180; ii, 527-529
   portrait of, i, 403
   on respiration, i, 91
   on salmon, ii, 92
   on sea-devils, ii, 547
   on trout, ii, 94
   on variation in vertebræ, i, 210
   on zones of distribution, i, 249, 251

 gunwale, ii, 512

 Gurley,
   on parasitic diseases, i, 342

 gurnard, i, 122, 198, 208, 209; ii, 456

 gurry shark, i, 547

 Gymnarchidæ, ii, 188

 Gymnarchus, ii, 188

 Gymnelis, i, 209; ii, 519

 Gymnocanthus, ii, 448

 Gymnocephalus, ii, 241, 310

 Gymnodontes, ii, 398, 411, 418, 422

 Gymnosarda, ii, 262

 Gymnothorax, i, 211, 274; ii, 152
   figure of, i, 458; ii, 154, 155

 Gymnonoti, ii, 159-161, 188
   order of, ii, 187

 Gymnotidæ, ii, 187

 Gymnotus, i, 391

 Gyrinidæ, ii, 222

 Gyrodus,
   figure of, ii, 22

 Gyrolepis, ii, 14

 Gyrosteus, ii, 18

 Gyroptychius, i, 82
   figure of, i, 604


 habits of fishes, i, 152

 haddock, ii, 537
   figure of, ii, 536
   skull of, figured, ii, 536

 Hadrodus, ii, 22

 Hadropterus, i, 300
   figure of, ii, 311

 haë, ii, 117, 118

 Hæckel, i, 411, 511
   on origin of fins, i, 62

 hæmal arch, ii, 6

 Hæmapoph