THE ORDERS OF MAMMALS 441 



Odd-toed Hoofed Mammals. The horses, tapirs, and rhi- 

 noceroses which belong to this order are characterized by the 

 presence of an odd number of hoofed toes. The horses, zebras, 

 and asses of the horse family have but one functional toe on each 

 foot, and two lateral splints. The common horse, of which over 

 sixty domesticated races exist, is not now known in a wild state. 



FIG. 309. Zebra. (From Lydekker.) 



The Nubian ass is probably the parent of the domestic donkey. 

 The zebras (Fig. 309) are confined to Africa. The tapirs have four 

 toes on the fore feet and three on the hind feet. The American 

 members of this group have a long, prehensile nose. They feed 

 on soft plants and are hunted for their flesh. The rhinoceroses 

 are large, thick-skinned mammals with one or two epidermal 

 horns on the nasal and frontal bones. 



