CLASS REPTILIA: OEDEE TESTUDINATA, 



165 



CLASS III. REPTILIA. 



General Characteristics (see Table, p. 13). Reptiles*, 

 being cold-blooded, require nothing to retain the heat, and 

 so are covered only with naked skin, scales, etc. The three- 

 chambered heart does not send all the venous blood to the 

 lungs. Pure oxygenated blood, however, goes to the head. 

 Reptiles are most abundant in hot climates, those of cold 

 regions hibernating. They are generally carnivorous, and 

 swallow their prey whole. 



ORDER TESTUDINATA. 



General Characteristics. The Turtles have the skel- 

 eton on the exterior of the body. The vertebrae and ribs are 



'. 376. 



Skeleton of European Tortoise. 



* There eeems little resemblance "between a crawling reptile and a flitting song- 

 ster ; yet, in structure, reptiles are much nearer related to birds than to mammals. 

 This is shown especially in the fossil, reptile-like bird, Arcfuxopteryx. and the bird 

 like reptiles, Dinosauria and Ornithosauria. See Geology, page 183-5. 



