THE REPTILES 199 



tion on land, and together with the general shape of the 

 body, are also well adapted for swimming. 



PIG. 115. Alligator (Alligator mississippiensis). 



186. Distribution of the lizards, In a general way the 

 number of reptiles is greatest where the temperature is 

 highest. The tropics therefore abound in species, often 

 of large size, and usually of bright coloration. As one 

 travels northward the numbers rapidly dimmish, their size 

 is smaller, and the tints less pronounced. In all probability 

 not less than four thousand known reptiles exist, whose 

 haunts are of the most varied description. 



In North America the lizards are almost exclusively 

 confined to the southern portions, only a very few species 

 extending up to the fortieth parallel. Among these the 

 skinks (Eumeces) are most widely distributed. The blue- 

 tailed skink is probably the most familiar, a small lizard 

 eight or ten inches in length, dark green with yellowish 

 streaks and a bright-blue tail. On sunny days it may 

 sometimes be seen darting about on the bark of trees in 

 search of insects, upon which it feeds. 



One of the most familiar lizards in this country is the 

 "glass-snake," found burrowing in the drier soil of the 

 southern half of the United States east of the Mississippi. 



