140 Bulletin American Mnsetini of Natural History. [Vol. XII, 



2. Second lower molar enlarged, — OxY^^NiD^. Includes the genera Oxyana, 

 Patriofelis, Oxycenodon. 



,3. First lower molar enlarged, ^Pa;./EOXICTID/^. Includes the genera 

 PaltTOiiictis, Amhlyctonus , j^lurotheritim. 



Oxyaena lupina Cope. 



By a fortunate circumstance I am novv enabled to give a rather 

 full account of the skeleton of this species, which has hitherto 

 been only imperfectly known. At the time of my first trip into 

 the Big Horn Basin in 1880 the country was a wild, uninhabited 

 region, save for the occasional visits of roving bands of hostile 

 Indians, and any explorations there by a small party were at- 

 tended by no small amount of risk to one's personal safety. In 

 fact, I was advised by the commander of Fort Washakie, at that 

 time the base of our operations, that the trip was a hazardous 

 one, and that he would not undertake to answer for our safe con- 

 duct. We went through, however, without serious inconvenience, 

 but at the same time the collecting was not as thoroughly done 

 as it probably would have been under less .trying circumstances. 



On this expedition, among other things, I secured a part pf the 

 skeleton of this species, which was erroneously referred to Cope's 

 somewhat larger but closely allied species O. forcipita, in his 

 volume ' Tertiary Vertebrata.' In 1891, I conducted another 

 expedition into this same region for the American Museum, 

 ^t which time, through a general settlement of the country, the 

 former more hazardous conditions had been entirely removed and 

 undertakings of this sort were not accompanied by the same 

 risks of violence at the hands of savage Indians as formerly pre- 

 vailed. Our knowledge of methods of collecting had, moreover, 

 materially increased, and while the actual number of specimens 

 secured was perhaps less, yet a somewhat greater success attended" 

 our efforts, especially in securing those parts which had already 

 been washed out of the rhatrix in which they had been originally 

 i^mbeddfed. In this category comes the present specimen, a por- 

 tion of which had been collected by the expedition of 1880, and 

 the remainder by the expedition of 1891. 



During this latter expedition, a new method was employed for 

 securing the missing parts which had been washed out and cov- 

 ered up again by the accumulating debris. Wherever possible 



