NO. 8 MAMMALIAN FAUNA, BADWATER AREA — GAZIN I5 



described from the Uinta B horizon, shows that the Dry Creek speci- 

 men has molars rather similar, except that the parastyles are strikingly 

 more outstanding and the teeth are about 20 percent larger. Moreover, 

 the rib on the paracone, in keeping with the parastyle, is better de- 

 veloped. 



The lower teeth of E. anarsius are quite similar to those in E. 

 amaronim and about the same size, although the anterior premolars 

 may be relatively a little larger. E. amaronim includes all the lower 

 cheek teeth from P2 to M3, inclusive. In No. 21097 only P2 of this 

 series is missing, although the inner walls of Mo and M3 are not com- 

 plete. As Osborn has shown, these teeth are much like those in 

 Moropus; however, in the earlier form P2 is a relatively larger tooth 

 and M3 retains a prominent hypoconulid. Moreover, as observed in 

 occlusal view of the Dry Creek specimen, the crista obliqua in all the 

 cheek teeth following P2 joins the posterior wall of the trigonid some- 

 what more buccally and lower than in Moropus, so that the W-pattern 

 is not so well developed. 



HELALETIDAE 



Simpson (1945) included the Helaletidae in the Tapiroidea, an ar- 

 rangement which is distinctly preferable to including it, as Scott 

 (1941) has, in the Rhinocerotoidea. Scott, moreover, included the 

 hyrachyids in the Helaletidae, and although there is much to be said 

 for such a grouping, as the hyrachyids are in many ways intermediate 

 between the tapiroids and rhinocerotids and show certain marked 

 resemblances to Helaletes, nevertheless the family distinction as the 

 Hyrachyidae within the Rhinocerotoidea, as advocated by H. E. Wood, 

 II (1934) and retained by Simpson (1945), may well be more de- 

 sirable. 



The Eocene tapiroids are structurally a comparatively conservative 

 group, distinguished from one another by relatively small and seem- 

 ingly unimportant differences. Nevertheless, at least two families, the 

 Helaletidae and Isectolophidae, should probably be recognized for 

 North American forms. 



DESMATOTHERIUM Scott, 1883 



Originally described by Scott as coming from the Bridger Eocene, 

 it is now understood that the type of Desmatotherium guyotii came 

 from the Washakie beds (see Granger, 1909, p. 22) and is in all likeli- 

 hood upper Eocene rather than Bridgerian in age. Peterson (1919, 

 p. 127) was evidently in error in citing the locality for this specimen 

 as "Henry's Fork, Wyoming." 



