ELEPHANTS. 253 



African elephant has a convex forehead ; it is not now 

 FIG. 194. 



Heads of (A) African and (B) Indian Elephants. 



domesticated, and has not been for many centuries. 



This animal is destructively 



hunted for its tusks, which FlG 195 - 



furnish the valuable ivory 



of commerce. 



The two enormous spe- 

 cies of fossil mammals 

 known as mammoth and 

 mastodon belonged to the 

 class proboscidia, and differed but little from the ele- 

 phants in organization and in habit. 



PERISSODACTYLA. 



The perissodactyla are classified in three families, 

 represented by the horse, the tapir, and the rhinoceros. 



22 



