DAKOTA AND NEBRASKA. 19 



Many scientific men have said to me, in a few years these fossil remains will be 

 exposed even more abundantly than ever, by the erosive action of atmospheric 

 agencies, so that we may look for novelties for a half-century to come. In reply, I 

 can only say that during the summer of 1866 I examined with great care the ground 

 so diligently searched by Mr. Meek and myself in 1853, just thirteen years pre- 

 viously; also the ground looked over by me in 1856, eleven years before; and I 

 could find no evidence that during that time a single specimen had been exposed by 

 the rains. Even the debris around a Turtle or Oreodon head, which we had removed 

 thirteen years before, remained undisturbed. It is to be recollected that atmospheric 

 influences do not operate here as in regions east of the Mississippi. 



It is safe to say that not more than ten or fifteen inches of moisture ever fall in. 

 this district annually, and so thirsty is the air that it seems to absorb it all as quickly 

 as it falls. The specimens are scattered over a large district, and are not abundant, 

 and when once gathered from a certain area, the evidence seems to me clear that 

 fifty years would do very little towards replacing them by the erosion of the beds in 

 which the fossils are found. No amount of excavation would be productive of 

 important results. 



We answer the question, how did so many of these remains accumulate in these 

 localities in this way ? It has been shown by Dr. Leidy that the two extinct faunjB 

 of this region were composed of carnivorous and herbivorous animals, as at the 

 present time ; that the Oreodons and Merychyus were gregarious, like the recent 

 buflfalo and antelope of the west; that they were subject to the predaceous attacks of 

 the Hycenodons, the Drepanodon and Dmictis ; and as we know that animals of 

 similar nature at the present day frequent the borders of streams, — the herbivorous 

 for food or drink and the carnivorous for shelter, — that the borders or valleys of these 

 streams were the scenes of numerous conflicts, which were carried on by these savage 

 beasts not only after their prey, but among themselves, their bones would be left 

 in the valleys, and the high waters would sweep them down into the lake, where 

 they would be buried in the sediments at the bottom. We find examples occurring 

 continually in that country at the present time, which would throw much light on 

 the matter. The wolves watch the deer, antelope, and other feebler animals as they 

 go down to the streams to drink, and all over the wide bottoms are the skeletons of 

 these animals in a more or less perfect condition. It is not an uncommon occurrence 

 for a band of wolves to attack an aged bufialo, too old to offer a successful resistance. 

 He must always betake himself to the river, where he is not unfrequently drowned, 

 or is destroyed by the wolves on a sand bar or island. Annually thousands of buflalo 

 are drowned in attempting to cross the Missouri on the ice, as it is breaking up in 

 the spring. Their bodies have been seen floating down the Missouri at Fort Union 

 and Fort Clark by hundreds, and, lodging on some of the islands or sand bars in the 



