444 Bulletin. American Museum of Natural History. [Vol. XXXIV, 
Pelycodus tutus Copr, 1885, Tert, Vert., p. 
228, pl. xxva, figs. 1-8. Not P. tutus Cope, 1877. 
Notharctus venticolus OsBorn, 1902, Bull. Amer. 
Mus. Nat. Hist., Vol. XVI, p. 195. 
Type, No. 4715b, parts of upper and lower 
jaws, from the Lost Cabin zone in the Wind 
River basin, Wyoming. 
Distinctwe characters: Mi-3=18 mm.; sym- 
physis of jaw not codssified.° 
Referred specimens, Nos. 4726, 4728, 14637, 
14638, 14640, 14655-6, etc. The best of these 
specimens is a fairly complete skull and jaws, 
eter No. 14655, the teeth of which are here figured. 
The larger size sufficiently distinguishes 
this species from N. nunienus. Most of 
type. Comparison with the Bridger genera 
and species is difficult, as they have not 
been revised. Some of these later species 
show a rudimentary metacone (tritocone) 
on p*, a character not observed in any Lower 
Fig. 18. Notharctue ventécolus, “ocene Notharctid. The two Wind River 
upper and lower molars, slightly species are likewise primitive in the sutural 
ee ee eee oF mphysia mandibuls, which ig codssified in 
each series. Lost Cabin beds, : j ; 
Wind River basin, Wyoming. most of the Bridger species. 
Notharctus nunienus (Cope). 
Pelycodus nunienus Corr, 1881, Bull. U. 8. Geol. Geog. Surv. Terrs., Vol. VI, p. 
187; (P. frugivorus) 1885, Tert. Vert., p. 230 (Wind River specimens only) pl. xxva, 
figs. 4-5; Notharctus nunienus OsBorn, 1902, Bull. Amer. Mus. Nat. Hist., Vol. XVI, 
p. 195, fig. 22. | | 
Type, No. 4734, lower jaw with ps—-mzr. from Lost Cabin beds of Wind River 
basin, Wyoming. 
Distinctive characters: Mi_3=15 mm.; heel of mz; bicuspid; symphysis of jaw not 
coossified. 
To this species are referred a number of jaws and jaw fragments from 
the Lost Cabin beds. It is a little larger than P. frugworus and distinguished 
by the more strongly developed hypocones — not as strong, however, as 
in N. venticolus. The species would be considered a mutation of frugivorus 
except that the one is referable to Notharctus and the other to Pelycodus 
according to the distinctions established by Osborn. 
the referred specimens are larger than the. 
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