APPENDIX. 365 



internal, usually with a backbone; limbs never exceeding two pairs, 

 articulated and turned away from the great nerve inasses. Cerebro- 

 spinal nervous system. Page 318. 



Class I. Pisces (Fishes).— Breathe by gills ; heart usually of two 

 chambers ; limbs converted into fins ; blood cold. Page 338. Orders 

 6 : 1. Pharyngobranchii. Ex. : Laneelet (Amphioxus). Page 

 337. — 3. Marsipobranchii. Ex. : Lamprey (Petromyzon), Hag-fish 

 (Myxine). Page 339.-3. Teleostei (Bony Fishes). Ex. : Eels (Mu- 

 raenidfe), Herrings (ClupeidiP), Salmon and Trout (Salmonida^), Cod 

 and Haddock (Gadidie), Flat-fishes (Pleuronectida>), Perch (Percida-), 

 Mackerel (Seomberidie). Page 341. — 4. Ganoidei. Ex. : Bony Pike 

 (Ijepidosteus), Paddle - fish (Spatularia), Sturgeon (Sturio). — .5. Elas- 

 mobrauchii. Ex. : Sharks (Carcharidse), Dog-fishes (Scylliadie), Saw- 

 fishes (Pristis), Rays and Skates (Raiidie). — 6. Dipnoi. Ex. : Mud- 

 fish (Lepidosiren). 



Class II. Amphibia. — Undergo metamorphosis, Ijreathing when 

 young by gills and in mature state by lungs, either alone or associated 

 with gills ; blood cold. Orders 4 : 1. Orphiomorpha. Ex. : Cascilia. 

 — 3. TJrodela (Tailed Amphibians). Ex. : Water-newt (Triton), Axo- 

 lotl (Siredon), Mud-eel (Siren). Salamander. — 3. Anoura (Tailless Am- 

 phibians). Ex. : Frog (Rana), Toad (Bufo), Surinam Toad (Pipa), Tree- 

 toad (Hyla). — 4. Labyrinthodontia (extinct). Page 349. 



Class III. Eeptilia. — Breathe by lungs ; circulation imperfect ; 

 blood cold; skin secretes "plates." Skull jointed to backbone by a 

 single condyle. Orders 9 : 1. Chelonia. Ex. : Turtles (C'heloniida"), 

 Soft Tortoises (Trionycidae), Terra{)ins (Emydidae), Land Tortoises (Tes- 

 tudinidfe). — 3. Ophidia. Ex. : Vipers (Viporida^), Rattlesnakes (Cro- 

 talidae). Sea-snakes (Hydrophidfp), Boas and Pythons (Boida>). — 3. 

 Lacertilia. Ex.: Lizards (Lacerta), Iguanas, Monitors, Chameleons. 

 — 4. Crocodilia. Ex. : Crocodiles, Alligators. Gavials. 



The following orders are extinct : 5. Icbthyopterygia. Ex. : 

 Ichthyosaurus. — 0. Sauropterygia. Ex. : Plcsiosaurus. — 7. Ptero- 

 sauria. Ex.: Pterodactyl. — 8. Anomodontia (Dicynodon). — 9. 

 Deinosauria. Ex. : Iguanodon. — 10. Theriodontia. Pago S.o" 



Class IV. Aves (Bird.?). — Oviparous vertebrates having double 

 circulation, warm blood, lungs connected with air-sacs, and a covering 

 of feathers. Skull with single "condyle"; fore-limbs converted into 

 wings. Page 378. 



Sub-class I. Ratitse. — Sternum without median ridge for at- 

 tachment of pectoral muscles. Orders 1 : 1. Cursores (Rvmnors). 

 Ex. : Ostrich (Struthio), Emeu (Dromaius), Cassowary, Apteryx. Page 

 290. 



Sub-class II. Carinatse. — Sternum furnished with median ridge. 

 Orders 9 : 1. Natatores (Swimmers). Ex. : Penguins (Spheniscidie), 



