202 NORTHERN ZOOLOGY. 
+ 2. Geomys umBrinus. (Rich.) Leadbeater’s Sand-Rat. 
G. (umbrinus), super umbrinus subter griseus, gula pedibusque albidis, cauda 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. 
DESCRIPTION. 
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 whiskers 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-pouches 
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-mouse ; 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. The chin, throat, feet, and claws, are 
white. The fail is round and tapering, and is well covered with short grayish-white hairs 5 
the hairs on the sides of the fore-feet are rather stiff, and curve a little over the naked palms; 
those on the hind-feet are shorter ; the posterior extremities are situated far forward. 
DIMENSIONS. 
Inches. Lines, Inches. Lines. 
Length of the head and body - Ar 0 Distance from the posterior angle of the orbit 
x head : . 1 8 to the auditory opening 5 - O 6 
os tail E 2 « I 9 N9 oe 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 . con) 9 Length of the middle fore-claw : 0 43 
Diameter of the orbit, about 0 2 Distance from the heel to the tip of the mid- ; 
dle hind-claw ° é ° nee 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. 
