“198 NORTHERN ZOOLOGY. 
from each other by a naked furrowed septum, and surrounded by a small naked space ; their 
inner margins are a little arched or ventricose. 
The mouth is small, being contracted by an union of the lips behind the upper incisors. 
The cheek-pouches are large and pendulous, thinly clothed with short hairs, or sometimes 
almost naked, opening into the mouth by the side of the molar teeth. 
The eyes are small and far apart. There is no other external ear than a slightly raised 
margin to the auditory openings, which are large. 
Body cylindrical. Tail of moderate length, round and tapering, more or less hairy. 
Extremities short, with five short toes to each foot. The palms are naked, and have a 
remarkable callous protuberance, projecting like a heel at their posterior part. The second 
and fourth toes are united nearly the whole length of their first phalanges to the middle one 
by skin. The fifth toe is considerably smaller and much further back than these, and the 
thumb is the smallest of all, and is situated a little further back than the fifth toe. The fore- 
claws are long, compressed towards their roots, slender and awl-shaped near their points, 
acute and considerably curved; the middle one is the longest, the thumb one is small and 
more blunt, and the others are of intermediate sizes, proportionable to the length of their 
respective toes. The hind-feet are more slender than the fore-ones, and their soles, which 
are entirely naked, are narrower than the palms. The outermost and innermost hind-toes 
are situated further back than the other three, of which the middle one is the longest. The 
hind-claws are much shorter and more obtuse than the fore-ones, are excavated underneath, 
and are but slightly compressed. 
The fur resembles in quality that with which the meadow-mice are clothed. The tail and 
feet are covered with shorter and coarser hair. 
Hazsir.—The sand-rats burrow in sandy soils and feed on acorns, nuts, roots, 
and grass, which they convey to their burrows in their cheek-pouches. They 
throw up little mounds of earth like mole-hills, in the summer, but are not seen 
abroad in the winter, nor do they throw up earth during that season. Their 
pouches when full have an oblong form, and nearly touch the ground, but when 
empty they are retracted for three-fourths of their length. Their terior is very 
glandular, particularly round the orifice that opens into the mouth. 
Remarks.—M. Rafinesque-Smaltz, in 1817, founded his genus geomys on the 
hamster of Georgia (geomys pinetis), described by Mitchill, Anderson, Meares, 
and others, and referred to it, as a second species, the Canada pouched-rat 
(mus bursarius of Shaw). He at the same time ranged under another genus, 
named by him diplostoma, some Louisiana or Missouri animals, ‘known to the 
Canadian voyagers by the appellation of gawffres, and remarkable for their large 
cheek-pouches, which open forwards exterior to the mouth and incisors, to which 
they form a kind of hood. These two genera have been adopted by few 
