XVI INTRODUCTION. 



The class of MAMMALS is subdivided into three orders. 

 a. Beasts of prey (Carnivora). 

 ft. Those which feed on vegetables (Herbivora). 

 c. Animals of the whale kind (Cetaceans]. 



The class of BIRDS is divided into four orders, namely, 



a. Birds of prey (Incessores}. 



b. Climbers (Scansores). 



c. Waders (Grallatores). 



d. S\vimmers (Natatores). 



The class of REPTILES is divided into five orders. 



a. Large reptiles with hollow teeth, most of which are 



now extinct (Rliizodonts). 



b. Lizards (Lacertans). 



c. Snakes (Ophidians}. 



d. Turtles (Chelonians). 



e. Frogs (Batrachians). 



The class of FISHES is divided into four orders : 



a. Those with enamelled scales, like the gar-pike 



(Ganoids], fig. 157. 



b. Those with the skin like shagreen, as the sharks 



and skates (Placoids). 



c. Those which have the edge of the scales toothed, 



and usually with some bony rays to the fins, as 

 the perch (Ctenoids). 



d. Those whose scales are entire, and whose fin rays 



are soft, like the salmon (Cycloids"). 



II. Department of ARTICULATES. Animals whose body is 

 composed of rings or joints. It embraces three classes. 



1. Insects. 



2. Crustaceans, like the crab, lobster, &c. 



3. Worms. 



