MAMMALS OF MINNESOTA. 205 
‘““General Characters.—Size medium, nearly equalling that of 
Arvicola riparius (average total length of four specimens, 
126.25 mm.) Tail very short (average length in four speci- 
mens, 23.75 mm. from actual base, apparent length only about 
18 mm.) with a long terminal pencil. Ears medium, thick, 
well haired, superior border inflexed, giving them a promi- 
nence not seen in flat ears of the same size; antitragus medium 
(smaller than in A. oregonus), its anterior border becoming con- 
tinuous with the anterior base of the auricle, thus forming a low 
rim in front of the meatus as in dA. oregonus and Synaptomys 
coogerit. Fur everywhere long, full and soft. 
‘‘Color.—Upper parts everywhere uniform pale, buffy-gray, 
slightly grizzled by the admixture of black-tipped hairs; under 
parts white, the plumbeous color of the base showing through 
in places on the belly; tail more or less obscurely bi-color.”’ 
“Total length—(1) male, 124 mm.; (2) female, 121 mm.; (8) 
male, 183 mm.; (4) female, 127 mm. Tail—(1) 25 mm.; (2) 20 
mm.; (3) 25 mm.; (4) 25 mm. Hind foot—(1) 18.25 mm.; (8) 
18: 7.1mm; ;(.4)-17.5, mim, ” 
‘‘Mr. Bailey states that ‘‘the pallid Arvicolas seem to be com- 
mon at Fort Buford. They show a decided preference for the 
north side of steep hills. I have not found them on the south, 
southeast or southwest sides. The only reason I can suggest 
for this distribution is that the twilight (their favorite hour) is 
longer on the north side. The hills where I found them are 
all steepest on the north side, which may have some effect, 
though there seems to be no difference in the vegetation on 
different sides.” ‘‘Their food seems to consist largely of the 
flowers of certain plants. When these plants grow near there 
are usually pieces of stems and blossoms of Liatris graminifolia 
and Artemisia frigida lying about, but many other plants and 
grasses seem to be eaten. They feed largely upon the seeds 
of Eurotia lanata. Probably the bulbs of Liatris graminifolia 
form a part of their diet, as is the case with Arvicola austerus.” 
“Thave caught several grasshopper mice (Onychomys leucogaster) 
and western white-footed mice (Hesperomys leucopus sonoriensis) 
at their holes, and think these species either drive out the Ar- 
vicole or else inhabit the old holes.” They are found on the 
edge of the ‘‘Bad Lands” and from the fact that they live en- 
tirely in the hills and from their food it may be inferred that 
their habitat is the ‘‘Bad Lands.” 
