PAET II. 

 DESCRIPTIONS OF VERTEBRATE FOSSILS. 



DESCRIPTION OF THE FOSSILIFEROUS LOCALITIES AND ANCIENT LIFE OF KANSAS. 



The vast level tract of our territory occupied by the Niobrara Cretace- 

 ous, and lying between Missouri and the Rocky Mountains, represents a con- 

 dition of the earth's surface which has preceded, in most instances, the mount- 

 ainous or hilly type so prevalent elsewhere,- and may be called, in so far, in- 

 completely developed. It does not present the variety of conditions, either 

 of surface for the support of a very varied life, or of opportunities for access 

 to its interior treasures, so beneficial to a high civilization. It is, in fact, the 

 old bed of seas and lakes, which lias been so gradually elevated as to have 

 suffered little disturbance. Consistently with its level surface, its soils have 

 not been carried away by rain and Hood, but rather cover it with a deep and 

 wide-spread mantle. This is the great source of its wealth in nature's crea- 

 tions of vegetable and animal lifej and from it will be drawn the wealth of its 

 future inhabitants. On this account, its products have a character of uni- 

 formity; but, viewed from the standpoint of the political philosopher, so long 

 as peace and steam bind the natural sections of our country together, so long 

 will the plains be one important element in a varied economy of continental 

 extent. But they are not entirely uninterrupted. The natural drainage has 

 worn channels, and the streams How below the general level. The ancient 

 sea and lake deposits have neither been pressed into very hard rock beneath 

 piles of later sediment, nor have they been roasted and crystallized by internal 

 heat. Although limestone-rock, they easily yield to the action of water; and 

 so the side-drainage into the creeks and rivers has removed their high banks 

 to from many rods to many miles from their original positions. In many cases, 

 these banks or bluffs have retained their original steepness, and have increased 

 in elevation as the breaking-down of the rock encroached on higher land. In 

 other cases, the rain-channels have cut in without removing the intervening 

 reeks al once, and formed deep u r "i_ r e> or cations, which sometimes extend to 



