^#VX CONTENTS 



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THE VERTEBRATES i 



External characters i 



Internal characters 4 



Distribution lo 



History 12 



Classification 13 



Key to the classes of vertebrates 14 



CLASS I. FISHES 15 



On the identification of fishes 15 



Measurements 15 



Fins IS 



Lateral line .... 18 



Scales 18 



Color 19 



Head 20 



Teeth 21 



Internal structures 22 



History 22 



Number of species and distribution 23 



Key to the subclasses of fishes 23 



Subclass I. Cyclostomata 24 



Order i. Hyperotreta 24 



Order 2. Hyperoartia (Lampreys) 24 



Family Petromyzonidoe 24 



Subclass 2. Pisces (The true fishes) 28 



Division i. Selachii 28 



Division 2. Dipnoi 28 



Division 3. Teleostomi 28 



Series i. Ganoidei (Ganoid fishes) 28 



Order i. Chondrostei (Cartilaginous ganoids) 28 



Suborder i. Selachostomi 29 



Family Polyodontidae 29 



Suborder 2. Glaniostomi 29 



Family Acipenseridae (Sturgeons) 29 



Order 2. Holostei (Bony ganoids) 31 



Suborder i. Ginglymodi 31 



Family Lepisosteidae (Garpikes) 31 



Suborder 2. Halecomorphi " 32 



Family Amiidae (Bowfins) 32 



Series 2. Teleostei (The bony fishes) 33 



Order i. Isospondyli (Herring; trout) 34 



Suborder i. Clupeoidei 34 



Family i. Hiodontidae (Mooneyes) -. . . 35 



Family 2. Dorosomidae (Gizzard shad) 35 



Family 3. Clupeidae (Herring; shad) 36 



Suborder 2. Salmonoidei 37 



Family i. Coregonidae (Whitefish; 37 



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