412 HIPPOPOTAMUS. 
the formation containing the Mammalian fossils were 
collected and examined by him: of those shells he has 
determined twenty-four species, five terrestrial, and nine- 
teen fresh-water; of which latter, there appear to be three 
extinct species. All the others are existing and indigenous 
to Britain. In reference to this discovery, Mr. Lyell re- 
marks :—‘‘ The Hippopotamus is now only met with in 
rivers where the temperature of the water is warm and 
nearly uniform; but the great fossil species of the same 
genus (47. major, Cuy.) certainly inhabited England when 
the testacea of our country were nearly the same as those 
now existing, and when the climate cannot be supposed to 
have been very hot.” * 
We have no evidence that the great fossil Hippopotamus 
extended so far north as the Mammoth and tichorhine 
Rhinoceros, with which it is commonly found associated in 
England and the temperate latitudes of Hurope ; its re- 
mains are not uncommon in the pliocene deposits of Italy, 
and along the European shore of the Mediterranean. No 
remains of Hippopotamus major have yet been discovered 
in any part of Asia. The genus is represented in the rich 
fossiliferous tertiary deposits of the Sivalik Hills by a 
Hippopotamus with six incisive teeth in the lower jaw, 
from which difference its discoverers, Capt. Cautley and Dr. 
Falconer, have proposed for it the sub-generic name of 
Hexaprotodon. 
We have no evidence of the Hippopotamus having 
existed on our planet anterior to the pliocene division of 
the tertiary epoch: and the ancient extinct, like the recent 
species, seems to have been confined to the Eastern Hemi- 
sphere. 
* Principles of Geology, 1837, vol. 1. p. 144. 
