Si 



UlNTATHERIUM PRINCEPS, Sp. HOV. 



Established on several portions of the head, vertebral col- 

 umn, and the limbs. 



This species may readily be distinguished from the last 

 by its larger size, the broad nasals with small tuberosities, 

 the stronger zygomatic arches, and the sub-cylindrical centra 

 of the dorsal vertebras. 



The nasals are broad and flat for some distance behind the 

 tuberosities. Although the animal was not adult, the nasal 

 suture is almost obliterated, and is visible only on the in- 

 ferior surface ; in this respect it is very different from the U. 

 Icidianum, in which the suture persists throughout life; as is 

 shown by the type specimen, which was past maturity. The 

 tuberosities of U.princcps are lower, broader, and more everted 

 than in the preceding species ; are not divided by a groove, 

 but united together by a low rounded ridge, to which the sur- 

 face of the nasals gradually rises from behind. The portion 

 of the bones anterior is short, stout, and projects horizont- 

 ally. 



The median, or maxillary, projections are apparently short 

 and everted ; they are somewhat compressed antero-poste- 

 riorly, and enlarge rapidly downwards. They are transversely 

 oval in section. 



The posterior, or parietal, projections are different from any 

 that we have yet seen. They are sub-trihedral at base and 

 flattened antero-posteriorly above. The upper margin is 

 regularly arched, and is the thinnest portion of the process. 

 The posterior face is perfectly flat, and the parietal crest 

 makes a sharp angle with it, rising lower down than in U. 

 leidiamim; the frontal crest is also lower down than in that 

 species, and the anterior face is strongly convex. The inter- 

 nal margin is rounded and straight, and does not show the 

 longitudinal groove marked in the last species. 



The frontal has the eminences and depressions common to 

 the members of the genus; but the superciliary ridge is unus- 

 ually sharp and sinuous in outline. 



The squamosal is short, stout, and high ; is but slightly 

 curved outwards, but apparently projects somewhat down- 

 wards. The malar articulation is broad and flat, indicating 



