42 Mr. E. D. Cope on the 



Cyn^ELURUS, Wagler. Oueparda, Gray. 



C. jubatus, L. Africa, Asia, Persia, Cape of Good Hope. 

 ? C.ferox, Leidy (^Elurodon) . Loup River, Nebraska. 



The successive order of the modifications of structure 

 which define the above genera is not difficult to perceive ; 

 and it is interesting to discover that, as in other cases, it 

 coincides with the succession in geologic time. The typi- 

 cal genera Uncia, Felis, &c. are characterized by great 

 specialization ; and it is they which now exist. The oldest 

 found, Dinictis, Nimravus, &c, are the least specialized in 

 most respects, and they disappeared before the close of 

 Miocene time. 



Since one of the special characters of the Felidse is the 

 reduction in the number of the molar teeth by subtraction 

 from both ends of the series, an increased number of these 

 constitutes resemblance to other families. The germs Di- 

 metis, above defined, has been shown by Leidy to possess two 

 more inferior molars than Felts, or three more than Neofelis 

 and Lynx, as in the Mustelidge. The extinct Pseudcelurus 

 and the living Gryptoprocta have but one molar less than 

 Dinictis, lacking the posterior tubercular. Nimravus has the 

 same number of molars as Pseudcelurus, but lacks the first 

 premolar instead of the last true molar. In Hoplophoneus 

 we first find the number of molars as in the existing genera, 

 viz. pm. f, m. \. Other characters of this genus, however, 

 are of a generalized kind. 



I here recall the statement that the genera of Felida3 fall 

 into two series, which are distinguished by the forms of 

 the anterior part of the mandibular rami, and generally by 

 the large size of the canine teeth, to which the former are 

 adapted. This distinction appeared early in Miocene or 

 Oligocene time — in fact, in the oldest of the cats of which 

 we have any knowledge. The genera with large canines, 

 or Machasrodontine line, were then represented by Dinictis, 

 and the Feline line by Pseudcelurus. It is interesting to 

 observe that these genera differed from their latest prototypes 

 in the same way, viz. : — (1) in the presence of more nume- 

 rous inferior molars ; (2) in the presence of a heel of the 

 inferior sectorial ; (3) in the absence of an anterior cusp of 

 the superior sectorial. In the case of Dinictis one other 

 character of primitive Carnivora may be noticed, viz. the 

 absence of the cutting-lobes on the posterior edges of the 

 superior and inferior premolars, so distinct in the existing 

 cats. The same feature characterizes the superior premolars 

 of Pseudcelurus ; but the inferior premolars have the lobes. 



