1899.] 



IVort/nan, Restoration of Oxxccna lupiiia. 



145 



three cuneiforms have about the same relationship and arrange- 

 ment as in the modern Cats. Of the metapodials there is a dis- 

 tinct interlocking, although the degree is much less than in the 

 Felidae. The third is the longest but the second is slightly the 

 heaviest of the series. As in the fore foot, the claws are fissured 

 and non-retractile. 



Oxyaenodon dysodus, gen. et sp. nov. 



This genus is founded upon an unusually perfect half of a skull 

 from the Uinta Eocene, collected by the writer in 1896. It indi- 

 cates an animal of the size of a Gray Fox and is, therefore, if 

 properly referred to the Oxygenidae, the smallest member known. 

 The dental formula is the same as that of Oxycsna, viz. : I. f, C. 

 \, Pm. f, M. |, and the last superior molar is, moreover, trans- 

 verse. The chief distinctions between the two are seen in the 

 form of the skull and the character of the premolars, as well as tlie 

 great enlargement of the symphysis in the Uinta genus. In 

 Oxycenodon all the lower premolars are simple and have only rudi- 

 niental posterior heels, whereas in Oxyizna the heels of the 



Fig. 3. Oxy<enodo>i dysodus. Skull and jaw %th natural size. Type specimen, No. 2515. 



second, third, and fourth are large, and form important elements 

 of the crown. In Oxycenodon the third superior premolar has no 

 internal cusp, while in Oxya'na a well developed inner cusp is 

 present. The heel of the last lower, as well as the internal cusp 

 of the trigon, are more reduced in the Uinta genus than in 

 Oxy(Ena. In Oxycenodon the mandibular symphysis is enlarged 

 and extends back under the third premolar, the lower jaw being 

 relatively shallow and thick, while in Oxyc^na the mandibular 

 \_yune, i8gg\ 10 



