RODENTIA-ARVICOLIJSTAE-ARVICOLA AUSTERA. 
539 
ARVICOLA (PEDOMYS) AUSTERA, Leconte. 
Prairie Meadow-Mouse. 
Arvicola austerus, Leconte, Pr. A. N. Sc. Phila. YI, 1853, 405. (Wiscon6iu.) 
Aud. & Bach. N. Am. Quad. Ill, 1854, 289. (From Leconte.) 
Kennicott, in Agric. Rep. U. S. Patent Office for 1856, (1857,) 97, pi. xii. 
Sp. Ch.—- Size of A. riparius (4J inches.) Skull 1.10 inch. Winter fur long (half an inch.) Ears short, concealed, more 
than half the length of hind foot; thinly coated with long hair. Fore feet long and broad, more than half as long as hinder, 
which measure .8 of an inch. Half of sole hairy. Toes short. Tail short, scarcely longer than head, less than one-third the 
head and body ; the vertebrae 1£ times the hind foot. 
Above, pale cinnamon rufous, variegated with black, paler on the sides. Beneath, pure pale cinnamon, brighter than 
above ; the colors of. the back, sides, and belly melting insensibly in each other. Tail sharply bicolor, like the correspond¬ 
ing regions of body ; darkest at tip. Basal plumbeous of the fur becoming darker towards the extremity. 
Skull rather broad. Length to width as 100 to 56. Line of molars about one-fourth as long as the head. 
This species is of rather large size, and very stout in proportion to its length. The fur is 
only moderately soft, and thickly interspersed with long bristly hairs projecting considerably 
beyond the rest and overlaying them. The winter fur measures about half an inch above, half 
as much below, the summer fur about .35. 
The muzzle is short and broad, the whiskers shorter than the head ; brown and plumbeous. 
The ears are short and broad, completely concealed under the fur ; more than half the length 
of the hind foot; they are thinly covered with longhair on both sides except around the meatus; 
the antitragus is very large, semicircular, and apparently capable of closing the meatus 
entirely. 
The hind feet are rather small in proportion to the anterior, which are broad and quite 
fossorial. There is a short blunt claw attached to the obsolete thumb; the third finger is longest; 
the fourth a little shorter, the second claw extends to or a little beyond the base of the third; 
the tip of the fifth barely reaches the base of the fourth claw. The hind foot is apparently 
covered with hair for the posterior half of its lower surface, although a careful examination 
shows that the median line of this hairiness anteriorly is bare and overlapped by the lateral 
hairs. The toes are rather short; the first shortest, its claw scarcely reaching to the fissure 
between the second and third ; the third is longest, the fourth barely shorter ; the second still 
shorter ; the base of the fifth claw is opposite the fissure between the third and fourth. The 
claws are rather long, and considerably curved. 
The tail is short, the vertebrae scarcely longer than the head, in some specimens even shorter, 
it is well covered with appressed stiff hairs about equal in length, and there is a scanty pencil 
at the tip. 1 
The upper fur is dark lead color, becoming a little darker just before the grayish pale cinnamon 
tips. There are many long black hairs equally interspersed which relieve the cinnamon, and 
1 The following account of the head and feet, taken from an alcoholic specimen, will serve to give a jnore accurate 
idea of the portions of the body than what I have derived from the examination of skins merely. 
The head of this species is short and broad, as in the Arvicolae generally; the eyes rather large for the genus ; the 
muzzle hairy except on the septum. The upper lip is emarginate, but not actually cleft beyond the base of the incisors. 
The ear is quite large ; the membrane thickened; the anterior edge apparently not inflected ; the antitragus much developed 
into a semicircular valve capable of closing the meatus. The inferior edge of the ear, near its lower root, or what, perhaps, 
corresponds to the antitragus better than the valve, just referred to, is dilated more than in other forms of Arvicola, so as to 
render the auricle considerably broader than high. 
The palms are rather weak, the soles naked, with five tubercles. The hind feet are short, stout, and with but five 
tubercles, the posterior one on the outer edge of the sole being obsolete, or wanting entirely. The sole is densely hairy 
from the heel to the first tubercles. 
