THE AMERICAN BISOXS. 13 



The tooth from the lead-bearing crevices of Elizabeth, Jo Daviess County, 

 Illinois,* is undoubtedly, it appears to me, a tooth of Bison americanus, as Dr. 

 Leidy himself deemed "not improbable." 



A second upper premolar tooth from the post-pliocene beds of the Ashley 

 River, South Carolina,! is described by Dr. Leidy as presenting " nothing 

 characteristically different from the corresponding tooth of the recent bison," 

 but is provisionally referred by him to Bison lutifrons. It is, however, not 

 larger than the corresponding tooth of Bison americanus, and it seems to me 

 may have belonged to this species, or — and perhaps with greater proba- 

 bility — to the domestic ox, other remains identified as such by Dr. Leidy 

 having been found in the same beds. % 



The bison remains from Darien, Georgia, consisting of an atlas, part of a 

 humerus, a tibia and a metatarsal bone, referred by Dr. Leidy to Bison luti- 

 frons, nearly correspond in size with the remains of the smaller extinct bison 

 from the ice-cliffs of Eschscholtz Bay and California, and are hence too small 

 to belong to the male of the large Bison latifrons, but they may perhaps be 

 regarded as representing the female of that species. The atlas is one third 

 too small to fit the condyles of the original specimen of B. latifrons. Since, 

 however, the Georgia remains indicate an animal about one tenth larger 

 than the species represented by the remains from Eschscholtz Bay, described 

 by Dr. Richardson they are here provisionally referred to Bison latifrons, 

 although it seems almost equally probable that they may belong to B. anti- 

 ques. The following detailed description and the accompanying measure- 

 ments and figures (see Plate II) will perhaps aid in determining the 

 matter whenever additional material is discovered. 



The atlas from Georgia is a little larger than the largest atlas described 

 by Richardson, and referred by him to his Bison crassicomis ; it, however, 

 closely resembles it in form, apparently not differing more from it than 

 atlases of different individuals of the same species often differ. There is 

 only one important discrepancy, namely, the length of the centrum measured 

 on the dorsal aspect, which is disproportionately short, being scarcely longer 

 than that of a female B. americanus. Neither the Georgia specimen nor that 

 referred by Richardson to B. crassicomis differs much in form or proportions 

 from the atlas of Bison americanus, though materially in some respects from 

 that of Bison bonasus. All the atlases of the bisons of which measurements 



* Ext. Vert. Fauna, etc., p. 355, pi. xxxvii, fit;. 4. 



t Holmes's Post-pliocene Fossils, p. 109, pi. xvii, figs. 15, 16. 



t Ibid., p. 110. 



