114 Bulletin American Museum of Natural History. [Vol. XII, 



that there is comparatively little doubt that they do. They do 

 not display any special characters which will serve to distinguish 

 them from either the early Cats or Dogs. The more salient 

 features may be stated to be a moderately well-developed third 

 trochanter on the femur, a very slight grooving of the astragalus, 

 as well as a well-flattened distal end of the radius, all of which 

 belong to certain members of the early Canidae and Felidse. 



Uintacyon pugnax, sp. nov. 



This smallest known species of the genus is represented in the 

 collection by a single nearly complete lower jaw (No. 1744), bear- 

 ing the second and third molars in good preservation, together 

 with the roots of the remaining teeth. The jaw is remarkably 

 short and heavy, especially in the region of the symphysis, the 

 canine is not laterally flattened, and the premolars apparently 

 unreduced. The crowns of the second and third molars display 

 the usual cusps, but the trigons are more elevated than in any of 

 the preceding species. The length of the molar and premolar 

 series is 27 mm. 



Uintacyon edax Lcidy.' 



The type of this species and that of the genus is represented by 

 a moderately complete lower jaw preserved in the collection of 

 the Philadelphia Academy. The chief characters of this species 

 are seen in the comparatively shallow, elongated jaw, as well as 

 its smaller size. As already stated, the type displays an extra 

 premolar, which is undoubtedly abnormal, since it is placed with 

 its long axis transverse to the long axis of the jaw. Length of 

 molar and premolar series, including the extra premolar, 33 mm.; 

 canine not laterally flattened and premolars unreduced. 



Several fragments of jaws from the Big Horn probably represent 

 this species, but the specimens are so imperfect that the reference 

 is uncertain. 



Prodaphaenus scotti,^ gen. et sp. nov. 



We propose this genus upon a series of upper molars (No. 

 11,238) of the Princeton collection, together with a lower jaw (No. 



' Proc. Acad. Nat. Sci. Phila. 1872, 277. 



' This species is dedicated to Professor W. B. Scott, of Princeton, whose contributions to 

 Palseontology are so well known. 



