206 WoHman — Studies of Eocene Mammalia, etc. 



The type specimen of this species is from near Henry's Fork, 

 Bridger Basin, but others were found in the lower part of the 

 deposits. 



Limnocyon dysodus Wortman. 



OxycBnodon dysodus Wortman, Bull. Amer. Mus. Nat. Hist., June, 1899, 

 p. 145. 



The Uinta representative of this genus, as far as known, 

 while differing from the Bridger forms in rather strongly 

 marked specific characters, had, nevertheless, not departed suffi- 

 ciently from the general type to warrant the establishment of 

 a separate genus for its reception. It may well be that the 

 skeleton, when more fully known, will show characters which 

 will necessitate its removal from Limmocyon, but upon present 

 evidence, I choose to regard these characters as of no more 

 than specific importance. That it exhibits a distinct advance 

 in structure over the Bridger species, is shown by the fact that 

 the first lower premolar has become single-rooted, the two 

 external cusps of the first superior molar have been more 

 closely approximated, and the last upper molar is considerably 

 reduced in size. It would appear that this form is a direct 

 descendant of L. medius, which is the most abundant species 

 in the upper horizon of the Bridger, and that it was very proba- 

 bly also the forerunner of TKereutherium. 



[To be continued.] 



