1894.] Vertebrate Fossils. 243 
fossa is very shallow. The inferior dental foramen is large. 
The coronoid process is wide at the base and narrows rapidly 
toward the apex. The angleis produced but slightly down- 
ward. The inferior border is gently convex. 
The Teeth: Of the superior dentition the true molars and 
the fourth upper premolar alone are represented. They are 
larger than inthe recent rhinoceros but much smaller than 
in Aphelops as shown in Plate II, figs. 5,6, & 9. Molars two 
and three are best preserved and present the most distinctive 
characters. The dorsum is very flat, there is no median costa 
andthe anterior and posterior costae are only faintly represented 
On the posterior angle of molar three there is a well developed 
basal cingulum. The median sinus of this tooth is obstructed 
by a well developed anticrochet and crista. At the bottom 
and near the entrance of the median sinus is a small tubercle. 
Molar two has a faint crochet directly opposite the strong anti- 
crochet and a well developed crista as shown in Plate II, fig. 
6. There was a deep posterior sinus with a strong posterior 
vallum which in the type has been worn down so that the pos- 
terior sinus now appears as a posterior fossette. There is a 
very small anterior sinus and the anterior vallum is weak. In 
molar one and premolar four the teeth are so much worn that 
the anterior and posterior cross-crests are united through the 
anticrochet, and the inner portion of the median sinus appears 
as an accessory fossette. 
In the inferior dentition the last molar is placed well in 
front of the ascending portion of the ramus, it is but little lar- 
ger than molars one and two, and has a basal cingulum on the 
posterior border. The following are the principal measure- 
ments of the skull, lower jaw, and teeth. 
SKULL AND SUPERIOR DENTITION. 
Length of skull from end of nasal horn to behind post- 
tympanic process 
Depth of skull from middle of frontals to crown of teeth 235 
Width of skull in front of zygoma | .210 
