24 THE AMERICAN BISONS. 
says Richardson, “the aurochs, or Bison priscus of more recent paleon- 
tologists.”* To this form Dr. Richardson referred also a large horn-core, 
an atlas, several other cervical, dorsal, and lumbar vertebrae, a sacrum, 
parts of several innominate bones, two humeri, several radii, several im- 
perfect femora, and several metatarsals, chiefly on account of their large 
size. These remains, together with other bison remains of smaller size, were 
all from the ice-cliffs of Eschscholtz Bay, the smaller remains of this-collec- 
tion being provisionally referred by Dr. Richardson to “ Bison priscus?” The 
remains referred to Bison crassicornis are described in great detail by Dr. 
Richardson (the more important of which are also figured), and seem to 
differ in no important particular (except in being somewhat larger) from 
the corresponding parts of Bison americanus. Many of the slight differences 
he points out as existing between his Bison crassicornis and B. priscus? relate 
only to what would normally be included within the range of individual 
and sexual variation of representatives of the same species. All of the 
remains of his “ Bison priscus?” are smaller, with perhaps the exception of 
the fragment of a skull (No. 24,589 of Richardson’s work, figured in his 
plate vii), than the corresponding parts of the male of Bison americanus, 
some, perhaps of not fully grown individuals, being not larger even than 
the corresponding parts of the female of that species. The differences exist- 
ing between the remains referred by Richardson to “B. priscus?” and « B. 
crassicorms” are not greater than those that obtain between the two sexes of 
Bison americanus ; hence it seems possible that all of the bison remains 
described, from Eschscholtz Bay may belong to one and the same species, 
the larger representing the male and the smaller the female, of the form 
Richardson named Bison erassicornis, which is very probably the same as the 
B. antiquus of Leidy, and to which the California bison remains may be at 
least provisionally referred. 
To the same form I at first referred with much hesitation the bison 
remains recently discovered by Mr. Dall and others in Alaska. As these 
pages are passing through the press an imperfect skull} from the vicinity 
of St. Michael’s, Alaska, has also come to hand which seems to confirm the 
* Zool. of Voy. of Herald, as cited above. 
+ Received for examination from the California Academy of Sciences and labelled “ Bison americanus, 
St. Michael’s, Alaska, presented by the Alaska Commercial Company.” It is wholly unmineralized, and 
presents merely a weathered appearance, looking as a specimen might after only a few years’ exposure to 
the elements. 
