1915.] Matthew and Granger, Lower Eocene Wasatch and Wind River Faunas. ol 
For the most part the specimens are jaws or jaw fragments, but there 
are a few crushed or distorted skulls and in three instances an approach 
toward a skeleton. | 
The dental structure and osteology of the species has been thoroughly 
described and figured and there is but little to add. Comparatively few 
of the referred specimens show as long a p4 as the plesiotype, or as large a 
htypocone on the m’, but there are minute gradations between the extremes 
in these characters and they appear to be only individual, as are the differ- 
ences in the prominence of the various accessory cusps on both molars and 
premolars and the relative size of the last upper and lower molars. 
One of the two specimens from the Lost:Cabin, a maxilla (No. 14786) 
from Alkali Creek, Wind River basin, agrees almost exactly, except for a 
swelling of the mesostyles, with a similar specimen (No. 16058) from the 
P. vortmani 
(Topotype, Lost Cabin beds, 
Wind River basin, Wyo.) 
P. brachypternus 
(Topotype, Gray Bull beds, Big- 
horn basin, Wyo.) 
Fig. 6. Lower teeth, crown views, of speeies of Phenacodus. 
Clark Fork beds, and both of these are inseparable from the plesiotype 
from the Gray Bull beds. 
Phenacodus nunienus.'. Under this name Cope described some limb 
bones which he considered as belonging to the largest species of the genus 
and which possessed anatomical characters distinct from P. primeovus. 
He chose for his descriptions, measurements and figures a humerus and the 
lower end of a scapula which were found associated with jaws and frag- 
mentary skeleton material belonging to two or more individuals of P. 
primevus, and a skull, jaws and part of skeleton of Pachyena ossvfraga. 
~The humerus certainly belongs to the Pachyena specimen and probably 
also the fragment of scapula. Queerly enough Cope identified and figured * 
as the humerus of Pachyena a bone which undoubtedly belongs to one of 
the Phenacodus skeletons. | 
Phenacodus omnivorus*® was described by Cope from a last upper molar 
from the Wasatch of New Mexico, collected in 1874 (Nat. Mus. Coll. No. 
= ———————— SE Ae 
1 Tertiary Vertebrata, 1885, p. 434. pl. Iviig, fies..7, 8. 
2 Tertiary Vertebrata, 1885, p. 366, pl. xxilic, fig. 1. 
’ Rep. Foss. Vert. N. Mex., 1874, p. 11, 
