6 Field Museum of Natural History 



water where food is usually seized, without inter- 

 fering with breathing. A valve in the throat closes 

 the gullet while a bony palate separates the air cham- 

 bers in the head from the mouth, the internal open- 

 ing of the nostrils being at the very base of the skull 

 instead of in the roof of the mouth, as in other rep- 

 tiles. The gradual development of this bony palate 

 can be traced in the fossil ancestry of the Crocodilia, 

 and its progressive adaptation to special conditions 

 is an impressive example of evolutionary change. 



The American Alligator is found from the Rio 

 Grande in Texas, in the streams and bayous of the 



Fig. 3. 



The distribution of living Alligators is shown in black on the 

 map. The American Alligator (A) is found in southeastern North 

 America; the Chinese Alligator (B), in eastern China. 



Gulf coastal plain, throughout Florida, and in the 

 Atlantic coastal plain north to North Carolina. In 

 the Mississippi, it ranges northward as far as the Red 

 River. In former times it was abundant throughout 

 its range, but hunting for skins and sport has made 

 it scarce nearly everywhere. Possibly its most im- 

 portant remaining strongholds are the Everglades of 



[30] 



