SNAKES, TURTLES, LIZARDS, CROCODILES 



263 



shell is covered with a layer of fatty material which yields 

 considerable oil. The sight of turtles is very keen, for they 



Fig. 182. — Turtle's shell : 1^ . lower side or plastrou ; C, upper side, 

 or carapace. 



possess well-developed eyes. Unlike snakes, turtles are 

 furnished with legs. 



Crocodiles and Allig.itors 



Only one species of crocodile and one of alligator occur 

 in the United States. The crocodiles are rare and are 

 found only in the southern part of Florida. The alligators 

 are fairly abundant at present although gradually disap- 

 pearing and are found only in the southern states. 



Crocodiles. — Crocodiles are found in Florida, West 

 Indies, South America, and Africa, notably along the Nile, 



