78 ERA OF THE TERTIARY FORMATION. 



the lower jaw, by which it could have attached itself, like the 

 walrus, to a shore or bank, while its body floated in the 

 water. Dr. Buckland considers this and some similar 

 miocene animals, as adapted to a semi-aquatic life, in a region 

 where lakes abounded. Besides the tapirs, we have in this 

 era animals allied to the glutton, the bear, the dog, the horse, 

 the hog, and lastly, several felinse (creatures of which the 

 lion is the type) ; all of which are new forms, as far as we 

 know. There was also an abundance of marine mammalia, 

 seals, dolphins, lamantins, walruses, and whales. 



The shells of the older pliocene give from thirty-five to fifty ; 

 those of the newer, from ninety to ninety-five per cent, of ex- 

 isting species. The pachydermata of the preceding era now dis- 

 appear; but others enter upon the scene elephantoid animals, 

 the hippopotamus, rhinoceros, and horse. All of these bear a 

 striking resemblance to pachyderms of the same families still 

 existing. We have, in the mastodon and mammoth, which 

 succeed each other in the strata, elephants variously distin- 

 guished from the present by peculiarities in their dentition, 

 and hence considered as of different species, though this is a 

 purely arbitrary distinction. What is remarkable of these 

 ancient animals is their having lived in countries so far 

 beyond the present range of their family, namely, throughout 

 the whole temperate region of Asia and Europe, (England 

 not being excepted,) and even so far north as the seventieth 

 degree of latitude. The mammoth also inhabited North 

 America. Its chief external peculiarity was a pair of long 

 curved tusks extending forwards and upwards from the upper 

 jaw. The numerous remains of the animal in the most super- 

 ficial strata, and the discovery (in 1801) of a specimen with 

 its flesh and hide entire in a mass of ice at the mouth of the 

 Lena in Siberia, show that it must have lived down to compa- 

 ratively modern times. 



The pliocene gives many other new families. From 

 remains which have been found, however fragmentary in many 

 cases, there cannot be a doubt that all the principal mamma- 

 lian forms, except the highest and a few others, now existed 

 throughout the earth, and in species which only differed from 



