NIMEAVIDiE. 997 



Bemarks. — This species is nearly allied to the Hoplophoneus lorimcevus, 

 •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 short- 

 ness of the diastema, which is considerably less than in the Nebraska spe- 

 cies. With this animal it compares much as th^ bull-dog does with the 

 ordinary varieties of the genus Cams. 



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 wliich it doubtless 

 preyed. 



HOPLOPHONEUS CEREBRALIS Cope. 



American Naturalist, 1880, Dec, p. 850. Machwrodus cerebralis Cope, American Naturalist, 1880, p. 143 

 (January 31). 



Plate LXXVa; figs. 3, 4, 5. 



Probably the smallest species of the genus, and one that presents 

 peculiar characters. 



This peculiar species, the smallest of the genus, approaches nearest in 

 dentition to the true saber-tooths {Drepanodoii), and is represented by a 

 skull, from wliich the basioccipital region, a good deal of the right side, 

 and the lower jaw, are absent. 



It differs in many respects from all the members of this family of cats 

 heretofore discovered in North America. In almost every point in the osteol- 

 ogy of the skull it is peculiar. There is not as much space for the temporal 

 muscle as in most of the extinct species described, or as in the large recent 

 Uncice, but the points of origin of the muscle indicate that it was rela- 

 tively stronger than in the domestic cat and the lynxes. Its single pre- 

 molar is very small, so that tlie dentition for practical use is reduced, in 

 the upper jaw, to the canine and sectorial. Both have been most effective 

 instruments in the performance of their respective functions. The sectorial 

 has a distinct anterior basal lobe. The space for the accommodation of the 

 brain is relatively more ample than in any other feline of the formation, 

 -and the inner wall indicates that the convolutions of the hemispheres were 

 well developed. This species, if the cranium were of usual proportions, 

 "was about the size of the red lynx {Lynx ritfus). 



