MAMMALS OF MINNESOTA. 191 
‘The head is hardly to be distinguished from that of the deer 
mouse but the ears are smaller although they are obviously 
margined with white and otherwise in color and form as in JV. 
leucopus. The tail is about as long as in V. sonoriensis but is 
less densely hairy and has a broader dark stripe above. One 
of our Minnesota specimens (as figured) has both hands and 
feet snowy white while in more southern and eastern specimens 
they are said to be dark. The following measurements per- 
tain to the specimen figured:—length 5.63 ; tail 2.38 ; head and 
body 38.25;sole 0.68;forefoot 0.37 ;nose to eye 0.50; nose to ear 0.87. 
It will be seen that these measurements indicate a larger 
animal than usual, besides being one which in some other 
points approaches JV. /Jewcopus. Our Michigan mice are more 
domestic in their habits than the deer mice and may be en- 
countered about buildings even in towns of some size. One was 
taken, in 1877, in the basement of the University at Minneapolis. 
The range of the present species is rather more limited than 
that of other members of the subgenus but is nevertheless far 
less restricted than has been hitherto supposed. It is essen- 
tially a prairie animal, and will probably be found to be limited 
in range by the extent of the prairies as distinguished from the 
plains on the one hand, and the forest regions on the other. It 
may be found throughout the whole of the southern half of 
Minnesota, but is most abundant in the southwestern and south- 
ern portions. In Dakota it mingles freely with the Sonora 
mouse without exhibiting the least tendency to approach it in 
coloration, and on the east is gradually superseded to a very 
large extent by the deer mouse, from which it is even more 
evidently distinct. Upon the rolling prairies of the south and 
west it may be said to be alone in its own territory. Two very 
well marked varieties occur which, so far as the present writer’s 
experience goes, are, in a general way, connected with open or 
more umbrageous stations. Both varieties are found together 
in some cases, but the majority of the specimens found in Da- 
kota and to the south and west will undoubtedly be found to ad- 
here to one type of coloration and those in the east to another. 
On first encountering the Michigan mouse near Big Stone 
lake upon the western boundary I was inclined to imagine that 
a species hitherto unseen lay before me, so different was the 
whole ensemble, but comparisons and the variations exhibited 
by a large series of specimens made clear the essential conso- 
nance in most points with V. michiganensis. 
Inasmuch as this varietal difference is quite different from 
that mentioned by Hoy and Kennicott as separating H. bairdii 
from H. michiganensis it may be well to define it more minutely: 
