SOME EXTINCT CATTLE 261 
by the more slender and relatively longer horn-cores, 
and also by their upward and backward direction. 
From the characters of the skull it may be described 
as having horn-cores of moderate dimensions, with 
the basal girth equal to or slightly exceeding the 
length along the upper curve, with the section 
subcircular, and the direction curving regularly 
upwards and backwards. A nearly complete skeleton 
of this species was discovered about 1896 in the 
superficial deposits of Gove County, Kansas. 
The third extinct American species, B. crassicornis, 
is typified by remains in the British Museum obtained 
during the voyage of H.M.S. Blossom (1825-28) by 
Admiral Sir F. W. Beechey from the frozen cliffs of 
Eschscholtz Bay, Kotzebue Sound, Alaska, which were 
long referred to the European B.priscus. According 
to Mr. Lucas, the species is characterised by the 
great relative length of the horn-cores, which largely 
exceeds the basal girth, the horn-cores being 
slightly flattened on the upper surface, with the 
transverse much greater than the vertical diameter, 
and the direction decidedly backward, while the 
curve is regular, and the tips are not sharply reflected 
or directed distinctly backward. Although perfectly 
distinct from other American species, this bison may 
very probably have also inhabited north-eastern 
Siberia. 
Allen's bison {B. alleni), from the Pleistocene forma- 
tion of Idaho and Kansas, has long, slender, and 
much curved horns, slightly flattened above at the 
bases, with the transverse diameter considerably 
greater than the vertical, and the length along the 
upper curve much in excess of the basal girth. 
From B. crassicornis it differs by the much greater 
