42 Annals of the Carnegie Museum. 



the hypotype of H. uintensis was found at the eastern end of the 

 Uinta Basin near Wagonhound Bend Canyon on White River, Utah. 

 The specimen represents an animal as large as, or slightly larger, than 

 the type of H. iiintensis, and is here recorded for the convenience of 

 the student, because it differs from that specimen, and also from 

 H. imvianis Matthew, by the presence of a minute anterior cusp on 

 Pg-. P2- and also M3- are of larger size than is the case in the type 

 of H. uintensis. Since the type of the latter species consists of loose 

 teeth, which may possibly not all belong to the same specimen, no 

 great stress should at this time be laid on the differences noted. 

 The presence of the anterior cusp on P3- may also be an individual 

 character of the present specimen. The erection of a new species is 

 therefore not thought prudent. 



Family OXY.'ENID.E Cope. 

 Genus Oxy.enodon Matthew. 

 Oxyaenodon dysodus Matthew. 



Hycenodon sp. Osborn, Bull. Am. Mus. Nat. Hist., VII, 1895, p. 78, Fig. 3. 

 Oxyanodon dysodus Matthew, Bull. Am. Mus. Nat. Hist., XII, 1900, p. 49 



(type of genus Oxycenodon). 

 Oxycenodon dysodus H.\Y, U. S. Geol. Surv., Bull. 179, 1902, p. 759. 



(Specimen No. 1893 A.M.N.H.) 



Oxyaenodon dysclerus Hay. 

 Oxyanodon dysodus Wortman (mow Matthew), Bull. Am. Mus. Nat. Hist., XII, 



1900, p. 145. 

 Limnocyon dysodus Wortman, Am. Journ. Sci. (4), XIII, 1902, p. 206. 

 Oxycenodon dysclerus Hay, U. S. Geol. Surv., Bull. No. 179, 1902, p. 769; Matthew, 



Mem. Amer. Mus. Nat. Hist., IX, Pt. VI, 1909, p. 412 and 433. 



(Specimen No. 2515 A.M.N.H.) 



The above synonymy carefully worked out shows the status of the 

 two species of Oxycenodon as known at the present time. 



On comparing Oxycenodon dysodus Matthew with material repre- 

 senting Limnocyon the two appear to agree in the general structure 

 of the lower jaw. They have a very thick jaw with a heavy symphysis, 

 which extends backw-ard even with the posterior face of Pg-. The 

 dentition of the type of Oxycenodon dysodus IMatthew is very imperfect 

 and furnishes, unfortunately, small opportunity for comparison. 

 It represents an animal larger than the type of Oxycenodon dysclerus, 

 and further differs from the latter by having the chin gently turned 



