5 2 Bulletin American Museum of Natural History. [Vol. X, 



major proves to be a middle-aged male of A. fossigcr, and his 

 distinction of Teleoceras as a genus supersedes Aphelops Cope,' 

 because Cope° originally applied the term Aphelops to A. megalodus, 

 defining it as an Acerathere with only three premolar teeth in the 

 lower jaw. This is true of the type species {A. megalodus), but 

 this species should, so far as we know at present, be referred to 

 the genus Aceratlierimn, in which the lower premolars vary from 

 four to three in number according to age and individual variation, 

 as in the living Rhinoceros. 



Technically, however. Hatcher's definition did not clearly dis- 

 tinguish Teleoceras from Rhinoceros, a.?, he himself stated (f^?/'. cit., 

 page 245). Our abundant material proves not only that Teleoceras 

 is a Rhinoceros with a median horn on the tips of the nasals, but 

 that it is fully distinguished from the genus Rhinoceros as follows : 



Horns. Lower Premolars. Digits. 



Genus Rhinoceros . . Upon anterior portion of nasals. .4 in young, 3 in aged 



individuals 3-3 



Genus Teleoceras . . . Upon tips of nasals 3 in young, 2 in aged 



individuals 3-3 



The reduction of the lower grinders to 5 in T. fossigcr {a.'a com- 

 pared with 6 in Rhinoceros) is a very important and distinctive 

 character, as it absolutely excludes Teleoceras fossiger from the 

 ancestry of any of the modern Rhinoceroses, and shows it to have 

 represented a distinct side phylum, as Scott and Osborn had 

 already determined from its skeletal characters. 



Excavation of the Skeleton. 



The Phillips County Quarry,' near Long Island, Kansas, was 

 discovered in 1883 by Mr. Charles Sternberg, who collected for 

 the University of Kansas and for the Harvard University Museum. 

 From the latter collection Scott and Osborn procured materials 



' American Naturalist, March, 1894, pp. 241-246. 



2 ' On Some New Extinct Mammalia from the Tertiary of the Plains.' Palaeon, Bull. No. 

 14, Proc. Am. Phil. Society, July 25, 1873. 



'^ See Willistcin, ' Restoration <.>i Acerathermin fossiger Cope,' Kansas University Quarterly, 

 Vol. II, No. 4, April, 1894, pp. 289-290. 



