ART. 5. 



BISON OCCIDENTALIS FROM MINNESOTA HAY. 



offer distinct differences. The following table of measurements is 

 presented : 



A. Measurements of upper teeth of bisons. 



A fairer measurement for M ^ is on the outer face near the bone. 

 In each species this is 33 mm. 



It will be noted that the measurements of the premolars differ 

 little in the two species. In the case of the molars those of B. bonasus 

 are distinctly narrower than those of B. hison. Important differ- 

 ences are found on the outer face of the upper molars. In Pm * of 

 B. hison the three outer styles are narrower than the corresponding 

 ones of B. honasus, and the middle one does not extend out to a ruler 

 laid against the face of the tooth. In M ^ of B. hison the median 

 style lies mesiad of a line laid against the outer face of the tooth, 

 and it disappears much before the base of the tooth is reached. In 

 B. honasus this style projects out beyond a line extending from the 

 front to the rear style, and it continues quite to the base of the tooth. 

 In M - of B. hison all of the styles come out close to a line laid 

 against the tooth at the middle of the height; in B. honasus the 

 median style stands out much beyond a line from the front to the 

 rear style. In M ^ of B. hison the styles all extend out approximately 

 to the same line; in B. honasus the median style extends out far be- 

 yond a line joining the front and rear styles. It was formerly sup- 

 posed that Bison honasus and B. hison were closely related or were 

 even of the same species, but it appears that the American members 

 of the genus were more closely connected with one another than any 

 of them are with B. honasus. 



In his description of the skeleton of Bison occidentalism now in the 

 University of Kansas,* the writer gave the dimensions of various 

 bones of the limbs, and compared them with those of the existing 

 bison. Tlie same bones from the Minnesota collection, taken from 

 those chosen for a mount, liave been measured in the same wa3^ In 

 most cases these are slightly smaller than the corresponding ones 

 of the Kansas specimens; but yet somewhat larger than those of the 

 existing bison. However, a radius is 360 nun. long and 65 mm. wide 



*rroc. U. S. Nat. Mus., vol. 46, p. 173. 



