R. S. Lull — Primitive Pecora in Yale Museum. 113 



molar, the characteristic heel being absent. This molar 

 also lacked the posterior cingulum. H. tricostatus is 

 considered a synonym of H. calcaratus by Hay, and with 

 this the present writer agrees, for ont of twenty-four 

 individuals in the Yale Collection represented by the 

 upper molar teeth, the metastyle of M 3 varies from good 

 development to marked reduction in at least four speci- 

 mens, but is never entirely absent. The degree of devel- 

 opment of the posterior cingulum is also variable to total 

 obsolescence. As tricostatus is founded upon a single 

 specimen, it seems to represent merely the extreme of a 

 variational series of which the means were still extant 

 and therefore not a separate species but a varietal ten- 

 dency. Cope himself says in 1884 (p. 24) : "I know but 

 the one species, the H. calcaratus Cope," a statement 

 which, as Matthew rightly says, invalidates J?, tricostatus. 



Material from the John Day Formation. 



Hypertragulus hesperius Hay. 



Both Cope and Leidy have discussed hypertragulids 

 from the John Day Basin of Oregon, but have referred 

 them either to H. calcaratus or to Leptomeryx evansi 

 without further attempt at specific differentiation. Scott 

 has also figured John Day material belonging to this 

 genus under the name H. calcaratus. Hay, however, in 

 his catalogue, p. 675, gives the new name H. hesperius to 

 the John Day hypertragulids, with neither definition, indi- 

 cation of type, nor restriction to any one level. Doctor 

 Matthew informs me (personal communication) that Cat. 

 No. 7918, A. M. N. H., the specimen figured by Cope and 

 later by Scott, is to be regarded as the type. It consists 

 of the skull and jaws and a few fragments of the skeleton. 

 The matrix is "greenish tinged with buff and rather 

 hard" but there is no record of its exact level or locality, 

 save that it is from the John Day. The matrix color, 

 judging from the known distribution of the large amount 

 of John Day material in the Yale Collection, would indi- 

 cate middle John Day as the horizon of this type. 



Cope's description of H. hesperius gives no specific 

 characters other than that the size is the same as H. cal- 

 caratus, sometimes distinctly larger; later (1884, p. 25) 



