LIFE 



579 



remained. Rodents were represented by squirrels, beavers, 

 pocket -gophers, rabbits, and mice. Among perissodactyls, the 

 rapidly developing horse family was represented by Mesohippus 

 and Ancliif)f)iis. The rhinoceros tribe had deployed into three 

 branches, one a lowland form, ancestral to the existing family, one 

 aquatic, and a third an upland running form. The tribe had a cos- 

 mop Dlitan range. 



An erratic branch (the tUanotheres) of the odd-toed ungulates 

 which arose late in the Eocene reached its climax in the Oligo- 



Fig. 487. An interpretation of the elotheres, or giant pigs, of the White River 

 i.drawn by Charles R. Knight. (From drawing in American Museum of Natural 

 History. Copyrighted by the Museum.) 



cene (White River), and then disappeared. Its representatives 

 were distinguished by a long, depressed skull, armed with a pair of 

 horns near the end of the nose (Fig. 486). They reached some 

 fourteen feet in length and ten in height. They were American and 

 apparently rather local. Another odd type was the elothere, which 



