HISTORY OF THE CARNIVORA 559 



tritubercular pattern, except that the two outer cusps were 

 joined together, but the lower molars had lost all the internal 

 cusps, which gave them a carnassial appearance ; they were 

 not sectorial, however, for their cusps wore directly against the 

 upper teeth, not shearing past them, and were greatly blunted 

 and worn down by use. 



The last of the family was '\Harpagolestes, of the Uinta 

 and Bridger, one of the largest of the fcreodonts. The skull, 

 which was of disproportionate size, exceeded that of the Grizzly 

 Bear ; the upper profile of the skull had considerable resem- 

 blance to that of a bear in the steep forward descent at the fore 

 head. The teeth were more reduced than in the other mem- 

 bers of the family through the loss of the second premolar and 

 third molar of the upper jaw. The skeleton is little known, but 

 the humerus had a long and prominent deltoid crest and an 

 epicondylar foramen. 



In the middle Bridger stage were closely allied and very simi- 

 lar genera, ■\Mesonyx and \Dromocyon (Fig. 139, p. 269), which 



m.2. 



Fig. 276. — Upper teeth, right side, of fMesonyx obtusidens, showing the 

 grinding surface. 



were like small, big-headed wolves, for the skull was as long as 

 that of a Black Bear. Though the cranium was very long, the 

 brain-chamber was very small and the sagittal crest enormously 

 high, to afford surface for the attachment of the powerful jaw- 

 muscles. The tympanic bullae were ossified and had quite 

 long, tubular entrances, a feature which has been found in no 

 other fcreodont skull. The face and jaws were also elongate, 

 giving the head quite a wolf-Uke appearance. The neck and 

 body were of moderate length, but the tail was extremely 

 long, slender and whip-like. 



