CORYPnODON. 
209 
Coryphodon lobatus, Cope. 
Plate xlvi, figs. 2-10. 
This species rests on the remains of one individual, which I discovered 
together, and at a distance from those of any other animal. They consist 
of imperfect fragments of the cranium, with numerous more or less broken 
teeth, representing all positions in the jaws. These indicate the largest 
species of the genus. 
The characteristic last inferior molar offers certain distinctive features, 
which indicate that this animal cannot be referred to the C. radians. The 
posterior crest is low, especially on the inner side, where it is highest in 
C. radians, latidens, simus, etc., and rises from a broad, horizontal heel, or 
cingulum, which does not rise to the inner extremity of the transverse crest. 
Anterior to the latter, a crest with angular profile, or compressed lobe, 
extends nearly to the base of the anterior transverse crest, and its external 
base supports rugosities which continue into the posterior cingulum. There 
is no cingulum on the external side of the crown. The anterior descending 
crest is well developed, the lower part being quite elevated. The basal 
portions of the crown exhibit a rather fine rugosity of the enamel. An 
inferior premolar has a quadrate outline, and presents neither external nor 
internal cingula, and a slight one in front. Its size is large. The canines are 
very thick, but the crowns are not so long as in specimens of C. elepJiantopus 
and C. latidens. The inferior canine has the flat inner side of considerable 
antero-posterior extent, with a small angular projection in front at its base. 
The remainder of the crown is convex in section, but the posterior face is 
deeply worn by the attrition of the corresponding tooth of the superior series. 
The inner portion of the last superior true molar exhibits the usual 
characters, and is without a continuous cingulum at the middle. The 
penultimate superior molar has a continuous cingulum at the internal 
border and one across the external base of the posterior external crest, 
both of which are wanting in B. elephantopus and B. simus. Of the parts 
homologous with the two external crescents in Perissodactyla, the pos¬ 
terior V is remarkable for its small size, while the anterior is an elevated 
cone, compressed, and quite distinct from the former. The anterior cingu¬ 
lum is strong, and has been worn by attrition with an inferior molar. The 
14 G R 
