90 ERA OF THE TERTIARY FORMATION. 



.bivorous, and make a slight approach, to the cervine or deer 

 tribes. The common anoplothere was about the size of an ass, 

 but less elevated from the ground, and with a tail of above 

 three feet in length ; it is supposed to have been of aquatic 

 habits, and an expert swimmer and diver, but also given to 

 browsing upon land. Associated with these we find the first 

 example (chceropotamus) of an animal approaching to the hog 

 tribe, being nearest to the peccary of South America. 



We learn from the remainder of the Paris fossils, and from 

 others found in the eocene, that the earth now possessed fresh- 

 water reptiles ; serpents of the size of the boa ; natatorial, 

 wading, and rapacious birds ; rodents (dormouse and squirrel) ; 

 species allied to the racoon, the genet, and fox ; also bats and 

 monkeys. Lastly, the oldest tertiaries of America present us 

 with the Zeuglodon, a herbivorous whale resembling the du- 

 gong, having a stinted development of the extremities, but an 

 enormous tail, and reaching altogether the length of a hundred 

 feet. 



In the miocene sub-period, the shells give eighteen per cent, 

 of existing species, showing a considerable advance from the 

 preceding era with regard to the inhabitants of the sea. The 

 advance in land animals is less marked, but yet considerable. 

 The predominating forms are still pachyderms, and the tapiroid 

 animals continue to be conspicuous. Here occur remains of 

 the D mother ium, a creature said to exhibit an affinity to the 

 cetacea in the form of its head, and to the tapir in the cha- 

 racter of its teeth. It is most distinguished by its huge size, 

 being not less than eighteen feet long ; it had a mole-like form 

 of the shoulder-blade, conferring the power of digging for food, 

 and a couple of tusks turning down from 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. Be- 

 sides the tapirs, we have in this era animals allied to the 

 glutton, the bear, the dog, the horse, the hog, and lastly, 

 several felines (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 

 existing species. The pachydermata of the preceding era now 



