A BRIEF CLASSIFICATION OF ANIMALS 479 



SubphylumD. VERTEBRATA. 



Class I. Cyclostomata: Hagfish, Lamprey. (Figs. 68, 168.) 

 Class II. Elasmobranchii: Sharks and Rays. Dogfish. (Figs. 69, 



70, 120.) 

 Class III. Pisces. (30,000 species.) 



Subclass 1. Teleostomi. Mackerel, Trout, Cod, Perch, Goldfish, 



Guppy. (Figs. 71-74, 106.) 

 Subclass 2. Dipnoi. Lungfishes. (Fig. 75.) 

 Class IV. Amphibia. (2000 species.) 

 Order 1. Apoda: Coecilians. 

 Order 2. Caudata: Necturus, Salamander, Cryptobranchus, Am- 



blystoma. (Figs. 76, 77.) 

 Order 3. Salientia: Frogs, Toads. (Figs. 78, 98, 103, 107, 174, 175.) 

 Class V. Reptilia. (5000 species.) 



Order 1. Testudinata: Turtles, Tortoises. (Fig. 80.) 

 Order 2. Rhynchocephalia: Sphenodon. 

 Order 3. Crocodilia: Crocodiles, Alligators. 



Order 4. Squamata: Chameleons, Lizards, Snakes. (Figs. 81-83, 

 230, 231.) 

 Class VI. Ayes: Birds. (15,000 species.) 



Subclass 1. Archaeornithes: Archaeopteryx (extinct). (Fig. 233.) 

 Subclass 2. Neornithes. 



Division A. Ratitae: Apteryx, Ostrich. (Fig. 84.) 

 Division B. Carinatae: All familiar Birds. (Figs. 85, 86, 239.) 

 Class VII. Mammalia. (10,000 species.) 



Subclass 1. Prototheria: Monotremes. Duck-bill, Echidna. (Fig. 87.) 

 Subclass 2. Metatheria: Marsupials. Opossums, Kangaroos. (Fig. 



88.) 

 Subclass 3. Euiheria: Placentals. All familiar Mammals. (Fig. 202.) 

 Order 1. Insedivora: Moles, Shrews, Hedgehogs, Gymnura. 



(Figs. 201, 205, 207.) 

 Order 2. Edentata: Sloths, Anteaters, and Armadillos. (Figs. 89, 



204.) 

 Order 3. Chiroptera: Bats. (Figs. 207, 227.) 

 Order 4. Rodentia: Rats, Mice, Rabbits, Squirrels, Beavers, 



Porcupines, Guinea-pig. (Figs. 108, 187.) 

 Order 5. Carnivora: Cats, Dogs, Bears, Seals, Walruses. (Fig. 



104.) 

 Order 6. Cetacea: Whales, Porpoises, Dolphins. (Figs. 90, 206.) 

 Order 7. Ungulata: Horses, Tapirs, Rhinoceroses, Camels, Oxen, 

 Antelopes, Giraffes, Pigs, Hippopotami, Elephants. (Figs. 90, 

 92, 234, 238.) 

 Order 8. Sirenia: Manatee. (Fig. 91.) 



