540 



LAND MAMMALS IN THE WESTERN HEMISPHERE 



cranial base, such as the foramina, the imperfectly ossified 

 tympanic bullae, etc., were repeated in ^Dinictis, but the lower 

 jaw had much less prominent flanges for the protection of the 

 tusks. The limbs differed considerably from those of ]Hop- 

 lophoneus in being relatively longer and more slender and 

 retaining more primitive features, such as the larger third 

 trochanter of the femur. The five-toed feet were decidedly 

 small and weak, and the claws, though retractile, were less 



Fig. 266. - 



-Skull of ^Dinictis squalidens, White River. (After Matthew.) p. 4 = fourth 

 upper premolar, sectorial. 



so than in the other genus and were not hooded. The gait 

 was probably plantigrade or semi-plantigrade. 



The relationships of ]Dinictis and ^Hoplophoneus are 

 rather puzzling ; none of the known species of the former could 

 have been ancestral to the latter, for the two genera were 

 contemporaneous. ^Dinidis was apparently the somewhat 

 modified survivor of the ancestral stage and represented very 

 nearly the common starting point of both the feline and fmachai- 

 rodont subfamilies. Dr. Matthew has propounded the bold 



