1885.] Eocene Period of North America. 461 
of Opisthotomus are known from the same horizon and locality, 
from teeth only. The O. fagrans Cope is, with the Adapis mag- 
nus Filh., the largest species of the family. Sarcolemur Cope in- 
cludes a single species from the Bridger beds, of the size of the 
Flyopsodus paulus. It has in its sharp dental cusps an effective 
biting apparatus. 
In Notharctus Leidy, 
the fifth lobe of the true 
molars begins to be 
apparent, though it is 
only present in the 
first molar, where it is 
represented by the in- 
ternal extremity of an 
anterior crest. The ca- 
nine in this genus is Fic. 4.—Notharctus ep osus Leidy. a, mandible 
well developed. Only fom ie sae at Meggan Fos Pioa 
one species is certainly bess = Wyoming. From Leidy, ata U. S. Geol. 
y Terrs., F. V. Hayden, Vol, 1 
nown. 
More of the skeleton 
is known in the genus 
Tomitherium Cope 
than in any other one of 
the family, and its rela- 
tionship to the lemurs 
wasthusindicatedat the 
time of its original de- e 
scription in 1872. Un- 
fortunately the ungual 
phalanges remain un- 
known. As in Hyop- 
sodus and Pelycodus, 
there are but two infe- 
rior incisors in the low- 
er jaw, and these have 
transverse cutting 
iai Sa a ts a gg 
oe A em a í, 
edges, and are not pro- ied 
duced as in recent Fic. 5 Tomit m Cope, mandible 
i natu! I KE Y a, pete ear’ side; Fy ites above. Let- 
apapa ters as in Fig. 2 Original, from Report U. S. Geol. 
The first impression Survey Terrs., Vol. 11 
