THE AMERICAN BISONS. 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,t 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 latifrons. 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 lat- 
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. dadifrons. 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 
quus. 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 crassicornis ; 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. crassicornis 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, pl. xxxvii, fig. 4. 
t Holmes’s Post-pliocene Fossils, p. 109, pl. xvii, figs. 15, 16. 
# Wbid:, p. 110. 
