6 2 , Oxen
ranging from the date of the Norfolk forest-bed tg th e Ilford brick^earth.
A series of skulls in the British Museum shows considerable variation in
individual size, and also in the curvature of the horn-cores, but none of the
specimens display differences apparently worthy of specifigl distinction.1
Among these specimens are a skull and a detached horn-core obtained by
Captain Beechey from Eschscholtz Bay, Alaska, which were figured by
Dean Buckland, and subsequently made the types of B. crassicornis by Sir
J . Richardson. One of these has been identified by American writers with
F ig. 13.—Frontlet and horn-cores of the Plistocene Bison. From a specimen in the British Museum
discovered in the Plistocene brick-earth of Essex.
Leidy’s' B . antiquus, while the second been referred to yet another
species under the name of B. alaskensis. The British Museum has other
specimens from the Plistocene deposits of the Porcupine river, Canada;
and, taking European and American specimens together, the whole .series,
in my own opinion, should unquestionably be referred tHa single species.
Moreover, so far as I can see, the American specimens present no^closer
approximation to the living New World bison than do those from Europe
to its relative of the Old World. It may also be pointed out that during
the Plistocene period Asia and North America were almoSl certainly
1 The two skulls of the European species represented in Fig. 14 show a considerable sexual
difference in the width of the forehead and the size and curvature of the horns.
Plistocene Bison 6 3
connected .by way of Bering Strait, so .that it would be natural to expect
to«find identical animals on both side||of the line of these straits. And,
as a matter of fact, no one has disputed that the remains of the horse,
mammoth, and musk-oxgjttpnd in the northern parts of the two hemispheres'are
specifically identical.
p R ib ly there may be sub-specific differences, but it appears to me
neCSteary to accept the conclusi|j| that the Plistocene bison was a circumpolar
species, whose-.somewhat degenerate descendants developed on the
two. sides of the Pacific respectively into the living European and American
bfcpns, The earliest known bison in the Old World is the species of
which the remains,i occur in the upper Pliocene deposits of Northern
ItfSiaS and as the group may certainly be regarded as of Old World pfigin,
it seems very doubtful i f it entered America before the Plistocene epoch.
Hence I feel considerable doubt in admitting that certain remain||from
America are, as ;i$‘ stated to be the case, really of older Pliocene age.
The names of these are purposely omitted here, but allusion is made later
H>n to certain other remains; from various parts of America which may
indicate distinct species, and are in^'fev case of considerable interest from
a distributional point of view. In the eastern hemisphere this bison
doubtless eventually passed into the living European form, and in the
western’: into the woodland raceHf the existing American representative
K f the group.
The following are the dimensionBof the horn-cores of five specimens
in the British Museum. Several of these in their present condition show
some or all their dimensions exceeding those recorded in either of the
existing forms. And it must be remembered that to make a true comparison,
the horn-coref sof the latter should alone be measured ; in other
Words, the horny external sheaths should be added to the measurements
of the fossils, which would give a considerable increase ^ 9