THE REPTILES 191 
tion on land, and together with the general shape of the 
body, are also well adapted for swimming. 
Fie. 114.—Alligator (Alligator mississippiensis). 
180. 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 diminish, 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 (Humeces) 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 
“elass-snake,” found burrowing in the drier soil of the 
southern half of the United States east of the Mississippi. 
