MAMMALIA. 



327 



Of the genus Hippopotamus, which now lives on the 

 banks of the large rivers of Africa (fig. 232), the remains of 

 fossil species have been found in the sub-apennine and allu- 

 vial stages of Europe, North America, and India. (Pig. 234.) 



Of the genus Rhinoceros, we know ten species four are 

 found in the miocene stage at Eppelsheim and Sansan, the 

 others in the sub-apennine and diluvium of Europe. (Eig. 

 233.) Some of the fossil species ranged into latitudes which 

 are now constantly glacial regions, as the rhinoceros, with 

 its skin entire, found by Pallas in 1781, in frozen drift, near 



FIG. 233. Rhinoceros, from fresh- 

 water tertiary strata ; molar, 

 lower jaw. 



FIG. 234. Hippopotamus, molar, 

 lo\ver jaw. 



FIG. 235. Recent Elk, grinding 

 surface of molar, upper jaw. 



FIG. 236. Horse, from Brighton cliffs, 

 second molar, lower jaw. 



the Lena, at 64 North latitude. The diluvium and 

 caverns of England contain the remains of this genus. 



