572 



LAND MAMMALS IN THE WESTERN HEMISPHERE 



effective ; the fourth upper premolar and first upper molar 

 had large inner cusps, and in the latter the postero-external 

 trenchant ridge was shorter. The second upper molar, lacking 

 in ]PatrioJelis, was a transversely placed ridge, which engaged 

 the heel of the second lower molar. The latter tooth, though 

 larger than the first molar, was much less completely trenchant 

 than in jPatriofelis and retained a small internal cusp and quite 



Fig. 284. — Wxycena lupina, Wasatch stage. Restored from a skeleton in the 

 American Museum. 



large heel. The skull resembled that of the Bridger genus, 

 but the face was not so much shortened, the zygomatic arches 

 were not so widely expanded or so massive, the lower jaw was 

 not so heavy, nor the chin so steep. The body was relatively 

 longer and more slender, the ribs being thinner and the chest 

 shallower ; the tail was even longer, but not nearly so thick. 

 The articulations of the lumbar vertebrae were less complex. 

 Except for their greater length and slenderness the limbs and 

 feet were nearly identical with those of ■\Patriofelis. 



