form which has contributed its full share to the problems of systematic
zoology. Its remote and inaccessible range has greatly retarded
knowledge of its structure, and it is only within the last three years
that acquaintance has been made with its soft anatomy, and at the same
time with a maze of resemblances and differences toward other ruminants,
that perhaps more than equals the irregularities of the prong-buck. But
unlike that species, there is in the musk-ox no extreme modification,
such as a deciduous horn, to separate it distinctly from the rest of the
family. A recapitulation of these differences would be too minutely
technical for insertion here, and it must be enough to say that while it
cannot be assigned to either group, yet in the distribution of hair on
the muzzle, in the presence of a small suborbital gland, in shortness of
tail and the light color of its horns, it is sheep-like; in the absence
of interdigital glands, the shortness and stoutness of its cannon bones,
and in the presence of a small accessory inner column on the upper
molars, it is bovine. But in the coarse longitudinal striation of the
bases of its horns it differs from both. The shape of the horns is also
peculiar. Curving outward, downward and then sharply upward, with
broad, flattened bases meeting in the middle line, their outlines are
not unlike those of old bulls of the African buffalo.

At the present time the musk-ox inhabits only arctic America, from
Greenland westward nearly to the Mackenzie River, but its range was
formerly circumpolar, and in Pleistocene times it inhabited Europe as
far south as Germany and France. The musk-ox of Greenland has lately
been set aside as a distinct species. The most we can say is that
_Ovibos_ is a unique form, standing perhaps somewhere between oxen
and sheep, and descended from an ancient ruminant type through an
ancestry of which we know nothing, for the only fossil remains which are
at all distinguishable from the existing genus, are yet closely similar