454 Bulletin American Museum of Natural History. [Vol. XXXIV, 
quadrate bases, low crowns, distinct deuteroconidson p3_s. Lower canine of moderate 
size, two very small incisors. . Jaw short and deep anteriorly, front teeth vertical. 
Enamel heavily wrinkled. 
This genus is confined to the Bridger and chiefly found in the Upper 
Bridger although one specimen comes from near the top of the lower beds 
(Horizon B4). It is readily recognized by the peculiar construction of the 
molars, and the premolars are almost equally characteristic; they are short, 
wide, low-crowned, deuteroconid strong on p3_4, pi with quadrate base. 
The second premolar is less reduced than in the other genera, the canine is 
moderately large, and in front of it two very small incisors. Two speci- 
mens in the American Museum have the premolars and first molar complete 
and alveoli of the three front teeth; Wortman had concluded from less 
perfect material that there was probably only one incisor. I have not seen 
the upper teeth of Washakius; Wortman’s reference to it of a well preserved 
upper jaw in the Yale Museum appears to be well supported by the evidence 
and indicates that the hypocone is stronger in this genus than in any of the 
others from the American Eocene. The upper premolars have strong 
deuterocones, the molars are subtrigonal with small hypocone, no proto- 
style, minute conules, no mesostyle. The enamel of upper and lower teeth 
is heavily wrinkled, as in Hemiacodon. 
Shoshonius Granger 1910. 
Type, 8. coopert from Lost Cabin beds of Wind River basin, Wyoming. 
Generic characters: Upper molars tritubercular with small conules and a mesostyle. 
Lower molars with strong well separated paraconid and a distinct cusp postero- 
internal to the metaconid. M3 unreduced. Enamel with heavy vertical wrinkling. 
Upper premolars with strong internal cusps. Width of teeth moderate. 
This genus is closely allied to Washakius, from which it differs chiefly in 
the presence of a distinct mesostyle, the somewhat narrower molars and 
relatively larger trigonids, and absence of the cusp internal to the hypo- 
conulid. 
Shoshonius cooperi Granger 1910. 
Shoshonius cooperi GRANGER, 1910, Bull. Amer. Mus. Nat. Hist., Vol. XXVIII, p. 
249, fig. 5. 
a ype, No. 14664, upper jaw with p*m%, from Lost Cabin beds of Wind River 
basin, Wyoming. 
Specific characters: M!-3=6 mm.; m\_3=7 mm. 
