MURIDZ—ARVICOLINA—ARVICOLA AUSTERUS. 2 li 
Arvicola (Pedomys) austerus, BArrD, M. N. A. 1857, 539, pl. liv (teeth of specimen, No. 1247, from Lonisi- 
ana, queried as austerus), (Wisconsin, Illinois, Missouri, and Louisiana).—Covugs, Proc. Acad. 
Nat. Sci. Phila. 1874, 190. 
Arvicola (Pedomys) cinnamomea, Baird, op. cit. 541, pl. liv (teeth), (type, No. 2, Mus. Smiths., Pembina, 
Dak.). 
Arvicola (Pedomys) haydeni, BarrD, op. cit. 543 (type, No. 383%, Mus. Smiths., Fort Pierre, Dak.). 
DiaGNosis.—A. ripario subsimilis, veilere austeriore, forma robustiore, 
cauda breviore caput equante aut paulo superante; griseo-murinus, subtus ex 
albido plumbeus, brunneo dilute lavatus. Long. tot. 4, caude 1.25, pedis 0.70. 
Haxsrrar.—Western States and adjoining Territories, especially Illinois, 
Missouri, and Michigan. Kansas. Louisiana. 
Although this animal is subgenerically different from M/yonomes riparius, 
the superficial resemblance is so close that it is difficult to convey in words 
an intelligible notion of the distinctions. In fact, it looks more like M. riparius 
than like Pedomys var. curtatus, from which it is not specifically different. 
The following description is based upon about twenty specimens, mostly 
from Illinois. 
The pelage, though not harsh, is rather coarse, thick, and short, and does 
not lie smooth enough to possess much gloss; a condition suggesting the apt 
name “austerus”. The tail has an average hairiness, with a medium-sized 
pencil at tip. The ears are about flush with the fur on an average, but in 
scant-haired specimens may overtop a little. The soles are scant-hirsute for 
their posterior third, and 5-tubereulate, one of the tubercles of AZyonomes 
being wanting. The usual relative proportions of fore and hind feet and of 
all the fingers and toes obtain. In general form, the animal is stouter and 
seemingly clumsier than riparius; the tail is shorter, averaging little more 
than the length of the head, but sometimes reaching about one-third the whole 
length of trunk. The head /ooks broader than usual, with a very obtuse 
muzzle and rather short and sparse whiskers. 
The upper parts show an intimate “ grizzle” of black, brown, yellowish- 
brown, and grayish-brown, impossible to describe in a single word. This is 
darkest along the middle line of the back, whence it washes out lighter toward 
the sides. Some specimens, as No. 2444, are almost pure black along the 
dorsal area, and the other upper parts are correspondingly dark, showing 
merely a grizzle with grayish-brown, without any reddish. Others, again, as 
No. 2454, are as much lighter than the average, having no appreciably darker 
dorsal area, and the whole upper parts and sides of a light muddy-brown 
grizzled with brownish-gray. 
