1888.] 7 . [Cope. 
Further investigations may show this species to be identical with the 
B. pristinus Leidy. The differences at present apparent are: first, the 
one-rooted p. m. iv, two-rooted in B. pristinus ; second, the relatively 
rather smaller molars, especially the third superior. In the B. pristinus 
this tooth has a transverse series of tubercles on the heel which are rudi- 
mental in the B. trichenus, and the internal tubercle which stops the an- 
terior valley is wanting in the B. pristinus. As compared with the 
Chenohyus decedens this species has 1 longer premolar region, and larger 
anterior molars and premolars. 
BOTHROLABIS ROSTRATUS Cope. Spec. nov. 
A cranium nearly entire, but without mandible, represents this species. 
The specimen indicates a species of larger size than the white-lipped pec- 
cary (B. labiatus), but of more slender proportions. An important char- 
acter is found in the small size of the molar teeth. In this respect it com- 
pares with the B. pristinus much as the black bear compares with the 
grizzly. 
In profile the interorbital region is concave, and the sagittal crest rises 
above it. The prefrontal region is gently convex, and the top of the muz- 
zle is a gradually descending straight line. Viewed from above the outline 
is wedge-shaped to the contraction above the third premolar, and then ex- 
panded prominently for canine alveoli. The premaxillary region is not 
longer than in B. pristinus, while the facial part of the muzzle is consid- 
erably more elongate than in that species. Its profile has no such slope as 
is seen in B. subequans, nor abrupt descent as in Chanohyus decedens. 
There is no median frontal rib as in B. pristinus. The alveolus of the 
superior canine is produced downwards below the remaining alveolar bor- 
der, so that the fossa for the inferior canine is excavated into half the depth 
of the muzzle instead of only one-fourth as in the species already described. 
This may be a character of the males only. The zygomatic arch is pecu- 
liar in that the postorbital portion is considerably shallower than the 
orbital portion. Its postorbital process is large. The postorbital processes 
of the frontal are both broken at the apices, but so far as preserved they 
resemble those of the other species. A little process extends into the 
orbit from its anterior border, below which the latter is not very well de- 
fined. The orbit is not very large, and its long axis is oblique anteropos- 
teriorly and in the vertical plane. The posterior apex of the zygomatic 
process of the squamosal is broken, but it was evidently not so robust as 
in the species already described. The postglenoid is transverse and com- 
pressed to an acute free edge, and the posttympanic plate is closely 
appressed to it. The paroccipital process is elongate, and the apex con- 
tracts from the base. The latter lies at an angle of 45° inwards and for- 
wards, rising from the edge of the otic bulla. The occipital condyles are 
small, and are laterally expanded. The otic bulle are placed longitudin- 
ally and are small regular ovals. Their transverse diameter is less than 
the width of the space between them, and equals the space between the 
external bases of the postglenoid and paroccipital processes. The basi- 
