THE AMERICAN BISONS. 



PART I. 



1. — Distinctive Characteristics and Affinities of the 



Bisons. 



Genus BISON Smith. 



Bos (in part) of many authors. 



Bison H. Smith, Griffith's Cuvier's An. King., V, 373, 1827. 



Urm Bojasus, Nov. Act. Acad. Nat. Cur., XIII, 2, 427, 1827. — Owen, Rep. British Assoc, 1843, 232. 



Harlanus Owen, Proc. Acad. Nat. Sci. Phila., 1846, 94. 



Bisonlina Rutimeyer, Verhandl. d. naturforsch. Gesells. in Basel, IV, iii, 335, 1865. 



The bisons are easily distinguished osteologically from the other members 

 of the bovine family by the peculiar conformation of the skull. These dis- 

 tinctive features, as Cuvier * long since pointed out, consist in the forehead 

 of the ox being flat or slightly concave, while that of the bison is convex, 

 though somewhat less so than in the buffalo ; in the ox the forehead is also 

 quadrate, its length being equal to its breadth, while in the bisons the 

 breadth, measured at the same point, exceeds the height in the proportion 

 of three to two ; in the ox the horns are attached to the extremity of the 

 highest salient line of the head, or that which separates the forehead from 

 the occiput, while in the bisons the horns are placed considerably in front 

 of this line ; finally in the ox the plane of the occiput is quadrangular, and 

 forms an acute angle with the forehead, while in the bison it is semicircular 

 and forms an obtuse angle with the forehead. The genus Bison, as Dr. J. E. 

 Gray f was the first to point out, differs also from Bos in the peculiar form 

 of the intermaxillaries, which, as in the genera Po'cpJuigits and Bibos, are short, 

 triangular, and acute behind, not reaching to the nasals, as they do in Bos, 

 Bubalus, and Anoa. They gradually decrease in length from Po'cplmgus to 

 Bison, in which latter genus they are much shorter than in the others. 



* See Ossem. Foss., troisieme edition, Tome IV, p. 109, 1825. 



t Ann. and Mag. Nat. Hist., Vol. VIII, p. 229, 1846 ; Cat. Mam. Brit. Mus., Part III, p. 16, 1852. 



