1889.] NATURAL SCIENCES OF PHILADELPHIA. 211 



NOTES ON THE OSTEOLOGY AND SYSTEMATIC POSITION 

 OF DINICTIS FELINA, LEIDY. 



BY W. B. SCOTT. 



The problem of the origin of the Felidos and of their relations to 

 the other families of Carnivora is one of such obscurity, that any 

 information upon the subject, however slight, cannot fail to be of 

 importance. Of all the American felines (or Pseud ailuroids, as. the 

 case may be) the genus Dbiictis is probably the most primitive and 

 therefore the one best adapted to throw light upon the line of 

 descent through which the group has passed. A considerable amount 

 of uudescribed material of this curious genus has come into my 

 hands, among which there is an almost complete hind leg and foot 

 belonging to the Princeton Museum (No. 10,035), which has led to 

 the preparation of these notes. 



The Skull. 



The skull has already been described by Dr. Leidy (No. 8 1 , pp. 64- 

 65), but additional material enables me to supplement his account. 

 The most important of the specimens to be described is a fine skull 

 in the Academy's Museum, the base of which exhibits some most 

 interesting characters. 



As in the primitive carnivores generally, the cranium is very long 

 and narrow and is sharply constricted some distance behind the 

 orbits, which marks the anterior limits of the cerebral hemispheres. 

 Posteriorly the cranium is broadest and tapers forwards more reg- 

 ularly and more rapidly than in the Viverridce and the constriction 

 above mentioned is further back of the orbits than in that family, 

 occupying the same relative position as in Dajrfuemis 2 and other 

 primitive eynoids. Another factor which is of importance in the con- 

 struction of the cranium is the elongation of the posterior jwrtion of it, 

 that part lying behind the mastoid processes. This region in Dhiic- 

 tis, as in the viverrines, Cyiwdictis,' 2 and in most creodonts, is very 



1 See list of Authors at end of paper. 



2 '1 he American eynoids of the White River and John Day epochs, which 

 Cope has called Galecynus and Leidy has referred to Amphicyon, are for the most 

 part more nearly like the European Cynodiciis, under which name they are refer- 

 red to here, though a careful comparison would not improl ably show them to be 

 distinct. The White River dogs with 3 upper molars are quite different from the 

 true Amphicyons, and for these the name originally given them by Leidy, Daph- 

 ceiuts, should be revived. 



