Vol. 6] Merriam: Virgin Valley and Thousand Creek. 299 



form related to that represented by the larger teeth included in 

 the species referred to Sphenophalos nevadanus. 



ILINGOCEBOS ALEXANDRAS Merriam 



Ilingoceros alexandrae Merriam, Univ. Calif. Publ. Bull. Dept. Geol., 

 vol. 5, p. 320, 1909. From the Thousand Creek Beds of Thousand Creek, 

 Humboldt County, Nevada. 



Affinities. — Since publishing the original description of this 

 peculiar form, the collections from Thousand Creek have been 

 carefully examined for material which might furnish additional 

 information regarding its structure and affinities. Excepting 

 such information as has been presented above under the discus- 

 sion of I. schizoceras, nothing has appeared which suggests any 

 modification of the original description. The only light which 

 is thrown on the question of affinities of the genus Ilingoceros is 

 developed through study of the other remains representing ante- 

 lope forms obtained from the same formation. An examination 

 of the remains associated with those of Ilingoceros in the forma- 

 tion at Thousand Creek does, however, offer certain suggestions 

 which seem to demand consideration. 



Thus far in the collections at Thousand Creek the specimens 

 representing the dentition of antelope-like forms include only 

 hypsodont molar teeth. No short-crowned teeth like those of 

 Tragelaphus have been discovered. Also worthy of note is the 

 general absence from the outer side of the lower molars of promi- 

 nent styles or pillars such as appear between the columns of the 

 short-crowned lower molars of Tragelaphus and Strepsiceros. In 

 one or two specimens of molars from Thousand Creek small inter- 

 mediate styles are seen, but they are very poorly developed. 



When the first studies of the antelopes of the Nevada Ter- 

 tiaries were being carried on the writer was aware of the pres- 

 ence of several forms of large molar teeth of antelope-like forms 

 in the collections from Virgin Valley and Thousand Creek, but 

 was not at that time able to make certain as to the association of 

 the horns and teeth. Since the publication of the first paper it 

 has been shown that all of the large molar teeth with basal 

 intermediate styles were obtained from exposures in Virgin Val- 

 ley, which represent a much lower horizon than those of Thou- 



