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85 

 UINTA SELENODONTS 



The taxonomic position of Bunomeryx is from one point of view suf- 

 ficiently clear. As Wortman points out, it is obviously the direct descendant 

 of the Bridger Homacodon, and should be referred to the same family as the 

 latter. What this family should be called is another question, and one that 

 cannot easily be answered. The European Dichobune has upper molars of a 

 very similar type, and, so far as it is known, the rest of the structure seems to 

 agree very well with that of the American genera, which may perhaps belong 

 to the same family. It seems more probable, however, that the two groups 

 are distinct, the Homacodontidce standing in the same relation to the Tylopoda 

 as the DichobunidcE are believed by Schlosser to occupy with reference to the 

 Pecora. 



Family IV. OREODONTID/E. 



Protoreodon Scott and Osborn. 



Plate III., Figs. 19-23; Plate IV., Figs. 24, 25. 



Agriochaerus Marsh {non Leidy), Amer. Journ. Sci., 3d Ser., ix., p. 250. 



Eomeryx Marsh, Ibid., xiv., p. 364 {nomen nudum). 



Protoreodon S. and O., Proc. Amer. Phil. Soc, 1887, p. 257. 



Eomeryx Marsh, Amer. Journ. Sci., 3d Ser., xlviii. , p. 266. 



? Agriotherium Scott {non Wagner), Proc. Amer. Phil. Soc, xxxvii., p. 79. 



The essential features of the structure of this genus were quite fully de- 

 scribed in a previous paper ('89, pp. 487, ff), yet the recently made collections 

 add materially to our knowledge of it, and for the sake of completeness an 

 account of the skeleton will be given here, though that involves a number of 

 repetitions. Specimens of Protoreodon are about the most abundant of Uinta 

 fossils, though well-preserved ones are far from common. Even the best of 

 them have in nearly all cases suffered more or less from crushing, and it is 

 surprising to see how much the appearance of a fossil is changed according to 

 the direction in which the crushing has taken place. Especially is this true of 

 the skull. 



The oreodont family had already become distinctly established as such in 

 Uinta times, and is very clearly distinguished from the other contemporary 

 selenodonts. The genera of the succeeding White River stage differ com- 

 paratively little from those of the Uinta, of which Protoreodon is the most 

 abundant, as well as the most important. 



The dentition is peculiar and of considerable morphological interest ; the 

 teeth form a closed series without diastemata, and the formula is If, Cy, Pf, Mf. 



