meanings 
THE AMERICAN BISONS. 43 
Bison americanus, B. europxus. 
“ Carpus — Metacarpus . 1: 
Radius (Aussenseite) "1.102 > 3.387 (1.) 1.254 > 3.697 (1.) 
Humerus mit Trochanter 1.285 1.443 
Scapula vorderer Rand 1.795 1.843 
Metacarpus mit Naviculare 1.151 1.098 
Tibia aussen 1.379 > 3.999 (1.180) 1.588 > 4.489 (1.214).” 
Femur mit Trochanter 1.469 1.803 
Taking the same method of comparison with five specimens of B. america- 
nus and two specimens of B. bonasus (= europeus) as a basis, gives propor- 
tions not differing essentially from Riitimeyer’s, though the figures range 
ten to fifteen per cent larger, being probably based on larger specimens. 
Carpus and Metacarpus de Us / 
Radius 1.260 > 3.680 (1.) 1.327 > 3.901 (1.) 
Humerus (with Trochanter) 1.420 1.574 
Scapula 1.940 1.836 
Metacarpus 1.400 1.364 
Tibia 1.680 > 4.800 (1.180) 1.727 > 4.834 (1.155) 
Femur (with Trochanter) 1.720 1.743 
The differences between the two species in these proportions are very 
slight, scarcely greater in fact than occur between different individuals. of 
Bison americanus. 
Dr. J. E. Gray placed the aurochs and American bison in different sections 
of the genus Bison, the first of which, containing the aurochs, is character- 
ized as having the “tarsi elongate, fore and hind quarters subequal,” and the 
other, containing the American bison, as having the “tarsi short, hinder 
quarters very low.” In the description of the aurochs he says again, “ fore 
and hind legs subequal; tarsi elongate,” contrasting it with “tarsus short, 
hinder quarters very low,” in his diagnosis of Bison americanus. The differ- 
ence in height between the fore and hind quarters of the aurochs and 
American bison is, as already shown, more apparent than real, owing to the 
greater size of the pelvic region in the aurochs. The difference in the 
relative length of the tarsus is also much less than one might infer from 
Dr. Gray’s diagnosis. 
In Bison americanus the proportional length of the metatarsal bone to the 
length of the femur and tibia taken together is (in five specimens) as 29-31 
to 100; in Bison bonasus (two specimens), as 28 to 100, showing an actual 
slightly greater length of the metatarsal segment in Bison americanus. The 
