A NEW RHINOCEROS, TRKiONIAS OSliOKNI. FliOM 

 MIOCENE OF SOUTH DAKOTA. 



11 IK 



By Frederic A. Lucas, 



Ouralar, Divmon of Ojinparotin^ Awilunnj. 



I 



Tlie name Trajonla.s o.slxinii is proposed for a rhiiiocci-os from tho 

 Miocene, presumul)ly the Lower Titanotlieriimi In-ds of South Dakota, 

 represented In* the anterior part of the palatal portion of the cranium 

 bearing on the right side three incisors, a canine, and the first 



Fig. 1. — Anterior portion of cranium of Trigonias osborn 



three premolars, and on the left side the third incisor and first three 

 premolars. 



The generic name is given in reference to the triangular shape of the 

 cutting portion of the procumljent tooth, while the species is named 

 in honor of Henry F. Osborn, who has done so much toward increas- 

 ing our knowledge of the extinct rhinoceroses. The specimen bears 

 the number 3924, catalogue of fossil vertebrates, U. S. National 

 Museum. The species is remarkable from the fact that it possesses 



Proceedings U. S. National Museum, Vol. XXIII— No. 1207. 



221 



