1915.] Matthew and Granger, Lower Eocene Wasatch and Wind River Faunas. 488 
The ordinal and family position of this genus are very doubtful. The 
construction of the molars is not unlike some of the Tarsiide but is perhaps 
somewhat nearer to Phenacolemur. But the characteristic heel of this 
genus is not preserved in the type and only specimen of Nothodectes. The 
enlarged front tooth is indicated only by a small portion of the alveolus 
of the root; a slender caniniform tooth associated with the type specimen 
may belong in this alveolus but cannot be positively fitted, and is smaller 
than would be expected. A well marked diastema in front of ps3 indicates 
probably that the anterior premolars were absent; and the position of the 
mental foramen is probably but not certainly indicated as beneath the 
posterior end of m;. These characters accord best with the Apatemyide. 
- While clearly distinct from any described genus the position of Nothodectes 
can only be ascertained by more complete specimens. It is of interest as 
coming from the Clark Fork beds, but does not show near affinities to any 
known Paleocene genera. 
EXPLANATION OF PLATE XV. 
Arctostylops steini, lower jaw, inner (lower figure), outer and crown views. [En- 
larged to five diameters. Type specimen, No. 16830, base of Gray Bull beds, Clark 
Fork basin, Wyoming. 
