REPTILIA 



245 



but feed entirely upon fish 

 in that they have an 

 extremely long, nar- 

 row snout, which re- 

 sembles that of a 

 gar-pike. Little is 

 known as to the hab- 

 its of the gavials. 



Family Crocodil- 

 idae. — This group in- 

 cludes the old world 

 crocodiles and old 

 and new world alli- 

 gators. 



The common 

 American. alligator 

 (Fig. 137, A), Alli- 

 gator mississipvien- 

 sis, occurs largely in 

 the southeastern 

 States, living in the 

 smaller streams and 

 ponds. They usually 

 lie in shallow water 

 with only the eyes 

 and the nostrils ex- 

 posed. When bask- 

 ing on the shore and 

 disturbed by enemies 

 they take to the 

 water and quickly 

 seek the bottom, 

 where they bury 

 themselves in the 

 mud, from whence it 

 is difficult to dislodge 

 them. They are not 



Thev differ from the other Crocodilia 



Fig. 137. — Group of Crocodilia. A, Alligator missis- 

 Kippiensis; B, Crocodilus amencnnus; C, Gavialis gan- 

 geticus. (Redrawn, A and B, after Ditmars, C, after 

 Lydckker) . 



as large as the largest crocodiles, reaching a length hardly over 

 twelve feet. The female digs a large nest in the humus and dead 



