The Biology of the Crocodilia 37 



They are said by some writers to be extremely 

 abundant in the waters of the upper Amazon, 

 migrating to the flooded forests during the rainy 

 season and returning to the streams on the approach 

 of the dry season. According to Ditmars there 

 are five species of caiman of which the spectacled 

 caiman, C. sclerops, and the black caiman, C. niger, 

 are the most striking. The former is so named 

 because of the spectacled appearance due to the 

 swollen and wrinkled upper eyelids; it reaches a 

 length of eight feet and is said to be of a treacherous 

 disposition. The latter has a blunt snout like 

 the alligator and is the largest of the New World 

 crocodilians. 



THE AMERICAN CROCODILE 



Of about a dozen existing species of crocodile, 

 but one, the American crocodile, C. america- 

 11 us, is found in the United States, and it is 

 limited to the swamps and coast of southern Flor- 

 ida below Lake Worth; its greater sensitiveness 

 to cold is doubtless the cause of its not being 

 found so far north as the alligator. Its range 

 extends south through Mexico and Central Am- 

 erica into South America. It was first found 

 in Florida by Dr. Hornaday in 1875. It sometimes 

 reaches a length of fourteen feet. 



As has already been noted there is, besides cer- 

 tain structural differences, a marked difference in 



