7 
But the genus which associates more definitely the orders Carnivora 
and Quadrumana, is the Cercoleptes, which F. Cuvier* placed between 
the two. Its two cutting premolars and three true molars, with the co- 
Gssified rami of the mandible are truly Quadrumanous features, although 
it should on other grounds be regarded as a plantigrade carnivore. Sev- 
eral of the extinct genera of the Wyoming Eocene will prove to be allied 
to this form. 
Cercoleptes does not, however, present us with the ultémate original type 
of the Carnivora. Such a type must also generalize the seals, with their 
longitudinal, cone-bearing molars, and flat, fissured claws. Some of the 
seals also unite the scaphoid and lunar bones later in life than other 
Carnivora, hence we would reasonably look for the division of these 
bones in their predecessors. The flat-clawed genera of Wyoming} answer 
these demands. The genera Mesonyx and Synoplotherium presents us 
with a series of molar teeth which repeat each other in form, are com- 
pressed below, and bear conical cusps. The jaws in the latter genus are 
slender, and the canines tend to the great development seen in many seals; 
but principally, the scaphoid and lunar bones are distinct, and the claws 
flat and widely fissured. The tympanic bone is more like that of the 
bear, and some seals, than that of the digitigrade Carnivora. These 
genera, though probably good swimmers, were well removed from the 
seals in the structure of the long bones of the limbs, and were probably 
remote in their ancestry. 
In Oligotomus, Orotherium, Hyopsodus and similar forms, the conic tu- 
bercles of the lower molars have a slight alternation, and the posterior, 
which has a crescentoid section in wearing, inclines to connection with 
both the inner conic tubercles by low ridges. These ridges are fully devel- 
oped in Paleosyops so that we have a dental crest of two Vs, in the infe- 
rior molars. This in wearing produces the two crescents of Paleotherium. 
The addition of two tubercles on the inner side takes place in the higher 
forms, which terminates in the four crescent-bearing molars of the Rumi- 
nants. How this is done is proven later by examples from the maxillary 
teeth. In Orothertum vasacciense there is a tendency for the conic tuber- 
cles to be connected in pairs by low cross ridges. These ridges fully de- 
veloped produce the two cross-crests of Hyrachyus and Tapirus. In Rht 
nocerus the outer portion retains a crescentoid form, giving rise to an 
L-shaped crest. In Bathmodon diagonal ridges appear which would result 
in two Vs, as in Pale@osyops, were it not that both transverse and oblique 
elements of the posterior V disappear, leaving but one such in the middle 
and posterior part of the mandibular series. In Uintatherium the diag 
onal from the posterior crest never appears, leaving a transverse crest 
and a V on the true molars. 
In the superior molar series the flattening of the outer tubercles may 
* Dentes des Mammifers, p. 31. 
+ See the Flat-clawed Carnivora of Wyoming, by E. D. Cope, April, 1873, 
