1915.] Matthew and Granger, Lower Eocene Wasatch and Wind River Faunas. 97 
Cuboid; leaeth 3) 0 i ant ae et ee he ata Se ats 29. 
* < SOwidth- ob piexgaa ene: ee te le erent 20.7 
NSO UGE Es A aa re ek ee es a oes Cte nae 13.4 
ce oe een erie ie ain ey ce One caer ae LUM gt Sider emcee 14.7 
. depth: (including hook) <5.- 2... eS Is Pete tee: aie aa 28 .2 
Metatanal hh tenet: ace as ee ee ae eee haem 80. 
Hind foot; totel Jangih Winpioxd ee ee 232 
Pachyena gigantea Osborn 1892.1 
Type, No. 72, upper teeth, p?~4 m?*r;_ p*-m31. from the Wasatch of the Big Horn 
Basin, Wyoming. . 
Distinctive characters: Length of jaw about 450 mm., very robust and massive, 
teeth much larger and more massive than in P. ossifraga; upper molars wider trans- 
versely, metacones more connate, m3 unreduced. 
Fig. 84. Pachyena gigantea, lower teeth, ps—me, two-thirds natural size. No. 15227,. 
Gray Bull beds, Big Horn basin. 
To this species were referred in 1901 a fragmentary skeleton, No. 2959, 
and a weathered skull and jaws No. 2823. Two additional specimens are 
now referred, nos. 15227, upper and lower teeth, 15226 young lower jaws. 
with milk dentition. 
The fourth upper premolar of the type belongs, I suspect, to the milk 
dentition; it is much more worn than the teeth preceding or following it, 
and the tooth which I identify as p* in other individuals is quite different in 
proportions and construction. The lower milk teeth are well shown in 
No. 15227. PP; belongs to the permanent series but appears only a little 
later than the succeeding milk premolars. Dpe is a very small tooth, two- 
rooted, compressed, with distinct heel. Dps34 have nearly the same cusp 
construction as their permanent successors, but are much smaller and more 
compressed and the paraconid is rudimentary on dps, strong on dps. They 
are readily distinguishable from permanent teeth of a smaller species by the 
rectangular outline. They are not nearly so elongate as the milk premolars 
of Dissacus, the protocones much larger in proportion to the anterior and 
posterior cusps. : . 
The sagittal crest in this specimen is very high, although the animal was 
so young. 
1Osborn (& Wortman) 1892, Bull. ORE Mote wre: TV. 1B: fee, i ES. 
