THE AMERICAN BISONS. 31 
exceed some very stout ones that belong to the latter sex. In Table VIII 
‘are given measurements of nine specimens, — five male and four female, — 
selected to show the extremes of individual variation, and also the sexual 
difference in size and form. These specimens are also figured in Plate X. 
From this table it appears that the longest metacarpal of a female B. 
americanus exceeds by ten millimetres the length of the shortest correspond- 
ing bone of a male, and is only twenty millimetres — or less than one 
eighth — shorter than that of the largest male, while the transverse diame- 
ter of the stoutest male metacarpal is one tiird greater than that of the 
smallest female metacarpal. This gives a hint as to the wide differences 
that may be looked for in the proportions and size of corresponding parts 
of the two sexes in the extinct species. 
Synonymy and Nomenclature. — The remains of Bison antiquus were first re- 
ferred to under the name of Bos uwrus by Dr. Buckland, in 1831, the speci- 
mens being those collected by Captain Beechey, at Eschscholtz Bay. Other 
remains were next mentioned under the name Bison antiquus by Dr. Leidy, 
in 1852, this specimen being the one from Big-bone Lick, Kentucky. 
During the same year Dr. Richardson gave the name crassicormis to remains 
from Eschscholtz Bay, at the same time doubtfully referring other speci- 
mens to the Bison priscus of Europe. The name antiquus antedates that of 
erassicornis by only a few months, but unquestionably has priority. Dr. 
Leidy’s paper, in which antiquus was described, was read July 6, 1852, and 
published prior to the following October; Dr. Richardson’s brochure, con- 
taining his description of B. crassicornis, is dated October 1, 1852, but was 
published subsequently to this date. In case future discoveries show that 
the name antiquus refers to a different species, or proves to be the female 
of B. latifrons, the name crassicornis, of course, then becomes tenable for the 
smaller Northern and Western extinct bison. 
As already noticed, both the names antiquus and ecrassicornis have been 
regarded, even by Dr. Leidy, as synonymes of Bison latifrons, while by all 
foreign writers, except Richardson, all the remains of extinct bisons found 
in North America have been regarded as identical with the B. priscus of 
Europe and Asia, and in some cases as specifically undistinguishable from 
the existing aurochs. 
