766 



PliOCEEDINGS OF THE NATIONAL MUSEUM. 



guished from most specimens of equal size ascribed to B. honasus^ by 

 the more regular taper and curve of the horn cores and by the fact 

 that they are directed much more backward. 



So far as is known, however, tliis species is separated geographically 

 from any Asiatic species by the interposition of B. crassieornis and B. 

 occidentalis. The horn cores are much longer and less conical than in 

 B. occidentalis, while they are shorter and more curved than in the 

 great Bison latifrons. 



This species was founded by Professor Marsh ^ on a horn core found 

 in the Blue liiver near Manhattan, Kansas. A much more complete 

 specimen, deposited in Stanford University, California, was obtained 

 by Prof. C. W. Greene from the banks of the Snake River, Idaho, 

 about 9 miles above American Falls, in the gravel overlying the lava 

 beds, which are considered by Dr. Lindgren to be late Miocene or early 

 Pleistocene. 



Two molars found by Mr. W. H. Hackney in the auriferous gravel on 

 the south bank of the Snake Eiver, 10 miles from Glenns Ferry, Idaho, 

 are very possibly from this species. They are the largest teeth of bison 

 in the collection of the U. S. National Museum. 



Professor Cope's Bos crampianus from the Pleistocene sands of south- 

 ern Kansas is assigned to B. alleni, because on examinaticu, I find that 

 the horn core of B. crampianus is less triangular in section than one 

 would be led to suppose from the figure, and because this triangular 

 section seems to a certain extent to be the result of crushing to which 

 the specimens had been subjected. In size and curvature the two agree. 



Measurements of horn cores of Bison alleni. 



Type, No. 911, Mnseuiii of Tale College. 



Specimen in Stanford University 



Bos crampianus Cope 



Trans- j Circum- 



jj ^4. verse ference 



diameter, diameter, at base. 



Vertical 



Length Length 



along along 



npper lower 



curve. ', curve. 



Distance 

 between 

 tios of 

 horns. 



1,338 



Iuii)erfect at base. 



'Actual length, estimated lengtli of complete horn core 720. 



BISON FEROX Marsh. 

 (Plate LXXXI.) 

 Bison ferox Marsh, Am. Journ. Sci., XIV, 1877, p. 2.52. 



Type. — No. 910, Museum of Yale College. Pleistocene (?) of Nebraska.^ 

 Horn cores long, length along upper curve much greater than circuin- 



' Three very likely shdiild be known as Bison priscus or B. eurojxjeiis. 



* Am. Journ. Sci., XIV, 1877, p. 252. 



^I have ventured to call the horizon Pleistocene instead of Pliocene, as given by 

 Professor Marsh, since the specimen was not associated with other species that 

 would aid in determining its nge, while, on the other hand, no other species of 

 Bison is known from so low a horizon. 



