228 GEOLOGY. 



by the Auchenia or Llama. In Miocene times, however, they 

 were represented in Nebraska by several genera and many species. 

 One of the first, described by Leidy, was called Paebotherium Wil- 

 soni. It was only about as large as the domestic sheep. Protom- 

 erys Evansi was closely related to the preceding, and about the 

 same size. A musk deer (Sefitomeryx) Evansi, also occupied this 

 territory at this time. It had many characters, especially in the 

 form of its maxillaries, relating it to the deer. It was about the 

 size of the musk ox of Thibet. 



No family of animals was represented in that epoch by more 

 genera, species and individuals than the Oreontidaa. Leidy, who 

 first described them, called them ruminating hogs. The skull ap- 

 proached more nearly to that of the peccaries, though the upper 

 part had some characters uniting them with the camels. The mo- 

 lars were like those of ruminants, and resembled most nearly those 

 of the deer, but unlike modern ruminants, they had incisors in both 

 jaws. The canines resembled most nearly those of the hog. The 

 teeth, as a whole, formed an almost unbroken arch, a condition 

 found in few animals besides the quadrumanna. Like the hogs, 

 too, they had four toes on each foot, two being functional, and the 

 two on the sides being too elevated to touch the ground. They 

 were, therefore emphatically what Leidy called them, ruminating 

 hogs. They were, judging from the abundance of their remains,, 

 more numerous than any animals of those times. They were gre- 

 garious, and must have roamed over eastern Nebraska in countless 

 millions. In size they ranged from an animal not larger than a rac- 

 coon to one as large as a small elk. The most abundant was Oreo- 

 don Culbertsonii. It was slightly smaller than the domestic sheep. 

 I have occasionally seen a stratum in the Bad Lands which in 

 places was largely made up of their remains. The largest species 

 was probably O. superbus, whose skull was fourteen inches long. 

 Besides the many species of Oreodon at least five additional genera 

 of this family are known. The number of species clearly defined 

 of all the genera was not less than twenty-five. These animals 

 were, therefore, among the characteristic features of the Miocene 

 epoch, and during those times could probably have been found ev- 

 erywhere in America. 



The herbivora, however, did not hold undisputed possession of 

 the land. The happiness of these countless herds was interrupted 

 by most sanguinary enemies. The carnivorous mammalia were 



