account of the form of its claws and incisors. It is, indeed, intermediate between
these very nearly allied sub-genera, with respect to its claws and teeth; and its fur
also is finer than that of the spermophilus Hoodii, but less so than the fur of
tamias Lysteri. Its incisors are stronger and shorter, in proportion to its size,
than those of the other marmots, but less compressed, and more slender than those
of the squirrel. The claws likewise are rather more curved, and deeper at the
base than those of the marmots ; but considerably larger, and not so sharp as the
claws of a squirrel. The second toe from the thumb of the fore-feet is the
longest, as in the spermophiles, and not the third, as in the squirrels. Its ears
very much resemble the ears of a ground squirrel, but are not so much pointed.
I have been able to collect no certain information respecting the manners of this
little animal. Mr. Drummond obtained several specimens on the Rocky Mountains,
in latitude 57°, and noticed that it burrowed in the ground. Lewis and Clark say
that it is common to every part of the Rocky Mountains, where wood abounds.
D E S C R I P T IO N .
Form, of body, that of a spermophile or squirrel; head, rather large; legs, shorter than those
of a squirrel. Incisors yellowish, flattened anteriorly, and narrower behind, but not shewing
the fine and numerous grooves which are visible when the incisors of the Sciurus Lysteri or
quadrivittatus are viewed with a lens, Mouth situated about as far back as that of Arctomys
Hoodii. Forehead convex ; nose obtuse, covered with very short hairs, except a naked space
round the nostrils. Whiskers black, shorter than the head. A few long black hairs over the
eye, and on the posterior part of the cheek. Eyes, moderately large ; ears, rather larger in
proportion than those of A . empetra ; but smaller than the ears of Sciurus Hudsonius or
quadrivittatus, consisting of a somewhat triangular flat flap, much rounded at the apex, placed
on the upper or meesial side of the auditory opening, thickly clothed on both surfaces with
short hairs, and having a small doubling of the anterior margin to form a helix, which, where
it approaches the auditory canal, is covered with longer hairs. The fu r on the back is dark
at the roots, then pale-smoke-gray for a space, then brown, and, lastly, its tips are barred
with white and dark hair-brown. The colour of the surface, when the fur lies smooth, may
be termed a hoary brownish-gray. There is no vestige of a dorsal line. A yellowish-white
streak commences close behind each ear, and running backwards along the sides, terminates
at the hip. It is widest in the middle, being there three lines broad, and in some specimens
it is very faint on the neck, though its commencement at the ear is always distinct. The white
streak is hounded above and below between the shoulder and the hip by a pretty broad border
of brownish-black. The sides under the lower black border, all the ventral aspect, the inner
surfaces of the extremities, and the breast and throat, are of a soiled yellowish-white, some