850 On the Extinct Cats of America. [ December, 
sectorials of the lower jaw remains. Three or four species only 
are known as yet, all from North America. We- may expect, 
however, to find the genus in various parts of the world, wherever 
the beds occur which represent the time immediately preceding 
the epoch of the true sabre-tooths. The longest known species is 
the 
FHloplophoneus primevus Leidy, from the White River bad-lands 
of Dakota and Nebraska. It is about as large as the Canada 
lynx, and has long.and slender superior canines. A larger species, 
the H. occidentalis Leidy, from the same horizon and locality, is 
known from a single jaw fragment, as large as the corresponding 
part of the Mimravus gomphodus. Although the oldest mem- 
bers of the Mimravide yet known from North America, the Dre- 
panodon characters of the mandible and of the superior canine 
tooth are well developed, much more so than in the false sabre- 
tooth group of the later Truckee epoch. In Europe, however, it 
must be remembered that the latter division commences still 
earlier, in the Upper Eocene, in the genus /urogale Filhol. 
Hoplophoneus oreodontis Cope. 
This species is nearly allied to the Hoplophoneus primevus, of 
which it may be only a regional variety. It is distinguished by 
its shorter and wider face and palate, a character especially seen 
in the shortness of the diastema, which is considerably less than in 
the Nebraska species. With this animal it compares much as the 
bull-dog does with the ordinary varieties of the genus Cants. 
The two specimens I have described were found by myself on 
a denuded portion of the White River formation in Northeastern 
Colorado. At the same locality were multitudes of bones, mostly 
jaws, of fifty species of various orders of Mammalia and Reptilia, 
on many of which it doubtless preyed. 
Hoplophoneus cerebralis Cope. 
This peculiar species, the smallest of the genus, appr oaches 
nearest in dentition to the true sabre-tooths (Drepanodon), and = 
represented by a skull, from which the basioccipital region, @ 
good deal of the right side, and the lower jaw are absent. " 
differs in many respects from all the members ọf this family of 
cats heretofore discovered in North America. In almost every 
point in the osteology of the skull it is peculiar. There is not 
as much space for the temporal muscle as in most of the extinct 
