416 APPENDIX 



Subphylum D. VERTEBRATA. 

 Class I. CYCLOSTOMATA : Lampreys. 

 Class II. ELASMOBRANCHII: Sharks. Dogfish.! (15,000 

 Class III. PISCES: Cod, Trout, Perch. J species.) 



Class IV. AMPHIBIA: Frogs, Toads, Salamanders. (1400 



species.) 

 Class V. REPTILIA: Lizards, Snakes, Tortoises, Turtles, 



Crocodiles, Dinosaurs (extinct). (3500 species.) 

 Class VI. AVES: Birds. (13,000 species.) 

 Subclass 1. Archaeornithes: Archaeopteryx (extinct). 

 Subclass 2. Neornithes. 

 Division A. Ratitae: Apteryx, Ostrich. 

 Division B. Carinatae: All familiar birds. 

 Class VII. MAMMALIA. (3500 species.) 



Subclass 1. Prototheria: Duck-bill, Echidna. 

 Subclass 2. Metatheria: Opossums, Kangaroos. 

 Subclass 3. Eutheria: Sloths, Whales, Porpoises, Horses, 

 Tapirs, Camels, Cats, Hedgehogs, Bats, and the Primates 

 including Monkeys, Apes, Man. 



