■f 2. Geomys umbrlnus. (Rich.) Leadbeater’s Sand-Rat.
G. (umbrinus), super umbrinus subler griseus, gul& pedtbusque albidis, caud& grisea vestita longitudine capitis.
Leadbeater’s Sand-Rat, of an umber-brown colour on the dorsal aspect, gray below, with white feet and throat, and a
gray hairy tail, as long as the head.
D E S C R I P T I O N .
The head is large; the nose, wide and obtuse, and, with the exception of the naked margins
of the nostrils, covered with fur similar in colour and quality to that on the crown of the head.
The nostrils are small round openings, half a line apart, with a- furrowed septum* and having
their superior margins naked and vaulted; a narrow, hairy, upper lip, not exceeding a line
in width, separates the nostrils from the upper incisors. The luhiskers are white, and are
shorter than the head. The incisors are much exserted, and are without grooves on their
anterior surfaces, which are slightly convex, and of a deep yellow colour. The lips unite
behind the upper incisors, so as to form a naked furrow leading towards the mouth, which is
rendered more complete by the stiffness of the hairs on each side of it. The cheek-pouchès
are of a soiled buff-colour, and are clothed throughout their exterior surface with very short,
.soft, whitish hairs, which do not lie so close as entirely to conceal the skin. The middle of
the pouch is opposite to the ear, and its anterior margin extends forwards to between the eye
and the angle of the mouth ; its tip is rounded.
The body, in shape, resembles that of a mole. It is covered with a smooth coat of fur, of
the length and quality of that of a meadow-móuse; but possessing more nearly the lustre and
appearance of the fur of a musk-rat. For the greater part of its length from the roots
upwards, it has a blackish-gray colour. On the upper and lateral' parts of the head, and over
the whole of the back, the tips of the fur are of a nearly pure umber-brown colour, deepest
on the head, and slightly intermixed with chestnut-brown on the flanks. The belly, and fore
and hind legs, are pale gray, with, in some parts, a tinge of brown. The sides of the mouth
are dark-brown, with a few white hairs intermixed. Thé chin, throat, feet, and claws, are
white. The tail is round and tapering, and is well covered with short grayish-white hairs 5
fhe hairs on the sides of the fore-feet are rather stiff, and curve a little over the naked palms y
those on the hind-feet are shorter; the posterior extremities are situated far forward.
D im e n s io n s .
laches. Lines. laches. Lines.
Length of the head and body . 7 0 Distance from the posterior angle of the orbit
„ head 1 8 to the auditory opening . . 0 6
,» tail . 1 9 ,, ,, posterior part of the wrist
Distance from the end of the nose to the tubercle to the tip of the middle fore-claw 0 10
anterior angle of the orbit . 0 9 Length of the -middle fore-claw . 0
Diameter of the orbit, about 0 2 Distance from the heel to the .tip of the middle
hind-claw . . . . 1 0
Although this animal is not an inhabitant of the fur countries, the above
description has been inserted with the view of rendering the account of the genus
more complete. I received no information respecting its manners or food. The
specimen came from Cadadaguios, a town in the south-western part of Louisiana.
[63.] 3 ? Geomys ? bursarius. Canada Pouched-Rat.
Mus bursarius. S h a w , Linnean Trans., vol. v. p. 227, pi. 8.
Canada rat. S h a w , Zool., vol. ii. part 1. p. 100.
Geomys cinereus. ■ R a f in e s q u e -S m a l t z , Amer. Month. Mag., 1817.” D e s m a r e s t , Mamm. in notis ad pag. 315.
Hamster du Canada. D e s m a r e s t , Mamm., p . 312.
This animal was not seen by us on the late expeditions, and, as has been
mentioned in a preceding page (199)^ it is still a matter of doubt whether it ought
to be included in this genus or in the following one. The specimen figured by
Major Davies, in the Linnean Transactions, was of a pale gray colour, and nine
inches and a half long from the nose to the root of the tail, which measured twa
inches and a half. The belly was paler than the back, and the cheek-pouches
were covered with very short pale hairs. Its superior incisors were deeply
grooved in the middle, and more faintly close to their inner margins.
The tucan of Fernandez has been considered by some as identical with the
mus bursarius of Shaw, but without sufficient grounds. Fernandez describes it
merely as a fat, thick, gnawer, a span long, clothed with tawny fur, having a long
murine nose, short round ears, a short tail, very short legs, crooked claws; and
he adds that it is scarcely able to see in day-light, leads a subterranean life, and
feeds on roots and seeds, which it hoards up in its burrows. He also mentions
that there are several other kinds of moles in New Spain which cannot see at all.