MAMMALIA, 17] 
DESCRIPTION. 
Dentition precisely similar to that of the 4. Richardsonii.. Incisors orange-coloured. The 
shape of the scull resembles that of A. Franklinii, and in the size of its body it also cor- 
responds with that animal. Head broad, depressed; nose very obtuse, covered with short 
brownish hairs. -Cheek-pouches moderate sized. Whiskers strong, black. yes large ; eye- 
lids whitish. ars flat, semi-oval, and thin like those of a squirrel, covered with short 
adpressed hairs, which project a little beyond the margin at the apex. At the base both the 
anterior and posterior margins of the ear fold in a little and are hairy. 
The fur covering the ear behind is brownish-black, fading towards the posterior margin into 
pale brown. ‘The hairs lining the inner surface of the ear are pale brown. The upper aspect 
of the head is clothed with short yellowish-brown hairs. A stripe of a darker brown colour, 
slightly sprinkled with white, is continued from the hind head to the back, on each side of 
which, from the ears to the shoulders, the fur is hoary. ‘The whole dorsal aspect of the body 
is coloured by a mixture of blackish-brown and very pale wood-brown or brownish-white, so 
disposed that the whitish parts appear in small but not very distinct spots, which cover more 
space than the blackish tints which separate them from each other. These markings occupy 
only the tips of the fur, which is short, close, lies smoothly, and has considerable lustre. 
When blown aside, the fur presents an uniform brownish-black tint, from the roots to near the 
tips. The upper parts of the cheeks are hoary; their lower parts, the margins of the mouth, 
the chin, the throat, and all the under parts, the insides of the thighs and shoulders, and the 
fore and hind legs and feet, are of an unspotted very pale brownish-yellow colour. The hair 
covering the belly is, as in the rest of the spermophiles, thinner and somewhat coarser than 
that on the back. The colours of the back and belly mingle a little at their line of junction 
on the sides. The fail is linear, covered throughout with hair an inch and a half long, which 
is capable of a somewhat distichous arrangement. In this state it presents three longitu- 
dinal brownish-white stripes, and two brownish-black ones on each side of the vertebre ; 
one of the white stripes forms the margin of the iail, and the black one next it is the 
broadest. These stripes originate in the hairs being of a brownish-white colour at the root, 
then black, and so on in alternate broad rings to the tips, which are whitish. The animal 
when pursued resembles the A. Franklinii in carrying its tail horizontally, and it is most 
probable that the hairs will then stick out in every direction, when it will appear variegated 
and hoary but not striped. The rings of alternate black and white on the hairs of the tail of 
A. Franklinii are more numerous, smaller, and less distinct. 
The shape of the extremities is precisely the same as in the other American spermophiles. 
The fore-ones are proportionably larger than those of A. Richardsonii, or A. Frankliniti. 
Palms, naked ; thumb, larger than even that of A. Parryi, and armed with a thin, convex, 
obtuse nail, adhering closely to its phalanx. Claws black, and similar to those of A. Rich- 
ardsonii. The soles of the hind-feet are covered with hairs posteriorly, and furnished with 
naked tubercles anteriorly ; and the hind-claws are similar to those of the two spermophiles 
just mentioned. 
Z2 
