44 



REPTILES AND BATRACHIANS 



In the Alligators, genus Alligator, the fourth tooth 

 of the lower jaw, the largest, fits into a pit in the upper. 

 The ventral bony scutes are very thin, or even entirely 

 absent. 



Until the year 1870, when a species belonging to this 

 genus was reported from China by the explorer Swinhoe, 

 Alligators were believed to inhabit the New World only. 



The Common Alligator, A. mississippiensis, of the 

 South-Eastern United States, is still very abundant in 

 certain parts of its habitat, in spite of the fact that large 

 numbers are killed every year for the purposes of procuring 

 their hide. The head is nearly twice as long as broad, 

 the snout rounded at the end, and much depressed, 

 with the lateral outline almost straight. The fingers 

 are scarcely half, the toes about three-quarters, webbed. 

 In the adult the colour is dark green or blackish 

 above, yellowish with black cross bands in the young. 

 Although attaining a total length of fifteen feet, it is 

 sexually mature when only about eight. The rate of 

 growth of this creature is very much faster than is generally 

 supposed, as is shown by the following observations, made 

 by Mr. R. L. Ditmars, on the growth of a specimen in 

 the New York Reptile House. 



