10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I3I 



in length of cheek teeth and distinctly shallower jawed than the Bad- 

 water form. Moreover, P4 in the type of Osborn's species apparently 

 lacks the anterior cusp but has one more cusp on the posterior crest, 

 to judge by the illustration (fig. 2), resembling more closely the re- 

 ferred tooth, A.M. No, 1895. Mx is relatively smaller, and M2 in 

 Osborn's type has a higher trigonid and a less distinctly basined 

 talonid. 



Miacis gracilis Clark (1939) is, of course, a decidedly smaller 

 species and P4 is evidently characterized by two posterior cusps in ad- 

 dition to the cingulum, 



MEASUREMENTS IN MILLIMETERS OF LOWER TEETH 



IN Miacis, cf. robiistiis, u.s.n.m. no. 21087 



P4, anteroposterior diameter : transverse diameter 10.5 : 5.4 



Ml, anteroposterior diameter : transverse diameter of trigonid 13.0 : 7.5 



M2, anteroposterior diameter : transverse diameter of trigonid 5.6 : 4.3 



CONDYLARTHRA 



HYOPSODONTIDAE 



HYOPSODUS, cf. UINTENSIS Osborn, 1902 



Plate I, figure 3 



A single Hyopsodus upper molar, U.S.N.M. No. 21089, """^.y well 

 represent H. nintcnsis, although some doubt may be entertained as 

 comparisons involving such limited material cannot be entirely satis- 

 factory. The tooth is about intermediate in size between M^ and M^ 

 in the type, A.M. No. 2079, but resembles M- more closely than M^. 

 The Badwater molar measures 4.3 mm. long by 5.6 transversely. This 

 is too small to occlude properly with the type lower molar of Hyopso- 

 dus fastigatus Russell and Wickenden (1933) from the Canadian 

 Swift Current Creek beds. 



It is interesting to note that although the type, and presumably the 

 two referred lower jaws mentioned by Osborn, are from the Uinta 

 C of Utah, there is in the collections of the U. S. National Museum 

 a lower jaw from Uinta B at White River pocket. 



Mention may also be made of an upper Eocene occurrence of 

 Hyopsodus at the Beaver Divide. The specimen, an upper molar, 

 comparable in size to the Badwater tooth, was collected by Van Houten 

 in beds he early regarded as representing the Beaver Divide conglome- 

 rate. The locality in question is some distance away from the critical 

 Wagonbed Springs section and Van Houten has since doubted ^ the 



3 Personal communication. 



