PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 461 



Island, the entire carcass of a whale has been exhumed. At 

 Lubec, in Maine, the bones of another whale have been exhumed. 

 In Michigan, the teeth of the walrus have been exhumed from 

 one of the ancient sea beaches. Thousands of similar instances 

 have been noted, not only in the Mississippi valley, but further 

 east. The Atlantic coast was then further inland, say fifty miles. 

 in Maine, and not far from its present position in this neighbor- 

 hood. Tl)e line of coast southwards inclined further and further 

 from that now existing to the west, until Eastern Virginia, Flor- 

 ida, and Southern Alabama lay under the ocean. The Mississippi 

 river, from a width of nine miles at the junction of the Wisconsin, 

 increasing in many places to fifteen miles, reached a width of 

 twenty to fifty miles at the mouth of the Red river, and termi- 

 nated with a width of one hundred and fifty miles, according to 

 late geological surveys in Mississippi. In the interior of Nebras- 

 ka, east of the Black Hills, and about one hundred and forty miles 

 west of the Missouri river, upon the Niobrara river, was an island 

 sea about one hundred and sixty miles in diameter, filled with 

 fresh water, and stretching northward to the Red river of the 

 North, through that to Lake Winnepeg, and so on, extending 

 northwards as far as the Arctic Continent. The animals which 

 lived in that sea, great whales, great lizards, fish and turtles, are 

 preserved with remarkable perfection in the rocks. Between the 

 Rocky mountains and this island sea, there was dry land, 

 covered with trees very similar to those now found upon the 

 Pacific slope. Those found on the Pacific coast partake some- 

 what of the tropical character, showing that the Pacific ocean 

 had then the same warming influence upon the adjacent country 

 that it now has. Those woods upon this continent were tenanted 

 by five species of elephants, where none now exist; those of the 

 present epoch being confined to the Indian and the African Con- 

 tinents. There were three species of the mastodon in that 

 region, an animal, some of whose species are as much larger than 

 the elephant, as the elephant is larger than the horse. There 

 were seven species of the rhinoceros, one not much larger than 

 a good-sized Berkshire hog; two species of the hippopotamus. 

 There were, also, horses, the ox, the hog, and a variety of other 

 animals allied to the camel, the horse, the hog, the rhinoceros, 

 the bear, the leopard, the wolf, and still other varieties essenti- 

 ally different from any known at the present day. After the 

 ruminating animals had lived and flourished through the Eocene 



