PETERSON : NEW SULLINE REMAINS FROM THE MIOCENE OF NEBRASKA 317 
imbedded in the heavy premaxillary. The triturating surface is convex in all direc- 
tions by wear. The external margin has received the greatest abrasion. I? is less 
worn, is much smaller than i', and has a basal cingulum on the postero-internal 
angle. I* is the smallest of the series. This tooth. is more ovate in cross-section, 
the antero-posterior diameter being the greatest. The crown is surrounded by 
enamel which terminates posteriorly in an acute angle. There is no cingulum. 
The principal wear is located obliquely on the anterior half of the crown. All 
the incisors are divided by short diastemata. ‘The canine of this species is very 
heavy, rivaling that of Dicotyles tajacu. In the fossil the cross-section of the tooth 
is a more rounded oval than in the recent genus, but, as in the latter, the posterior 
border is narrower than the anterior. ‘There is a long gradual abrasion caused by 
friction with the inferior canine on the anterior face, which terminates in a rather 
( | 
Fig. 4. Anterior portions of the upper and lower jaws of specimen No. 1418, Carnegie Mus. Cat. of Vert. Fossil. 
} nat. size. 
blunt point, with traces of additional wear on the external face. ‘Twelve mm. 
above the point of the right canine, on the external face, is a peculiar broad open 
abrasion, extending quite across the tooth antero-posteriorly. On the left tooth is a 
corresponding abrasion not nearly so well defined. These rubbed surfaces may indi- 
cate the habits of the animal, at least I cannot account for the wear, except by sup- 
posing that the canine was used for rooting. P! is separated from the canine by 
diastemata, a very short one in front and a longer one behind. This tooth is one 
of the chief characteristics of this species. It is a small tooth with the single pro- 
