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 V. 

 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 3. 25 ;sole 0. 68 ;f oref oot 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 \ 7 . leucopus. 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 

 maybe 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 coloration, and on the east is gradually superseded to a very 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. 



Qn 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- 



