M'CEESNEY on DAKOTA MAMMALS. 



205 



MUIIID.^. 



Mus MUSCULUS, Linn. 



That the common House Mouse has successfully made his way to 

 this part of the world is suflaciently well attested by the number now 

 found here. 



Specimens taken do not present any appreciable variations either of 

 size or color from those taken elsewhere. 



Genus HESPEROMYS. 



Hespekomys leucopus sonoriensis, {LeC.) Coues. 



This variety of the Deer or White-footed Mouse is found all over the 

 prairie in this vicinity, and, under favorable circumstances, replaces the 

 common House Mouse. 



I have observed this Mouse breeding in the early part of May and 

 also in August. Three to seven usually constitute the litter as observed 

 here. 



The following measurements are those of a few of the specimens pre- 

 served. 



[Judging from the measurements, I suppose true leucopihs to be inclndecl in the 

 list.— E. C] 



Place of collecting 



Fort Wadsworth, Dak. 



do ... 



, do 



do 



do 



do 



do 



do 



do 



do....... 



Sisseton, Dak 

 , do 



Date of col- 

 lecting. 



July 19,1876 

 July -20, 1876 

 July a4, 1876 

 July 9,1876 

 Aug. 25, 1876 

 Sept. 3, 1876 



do 



Sept. 14, 1876 



do 



Sept. 23, 1876 

 Sept. 25, 1876 

 Oct. 4, 1876 



From tip of nose to— 



0.40 



0.45 



0.50 



0.44 



0.50 



0.46 



0.48 



0.43 



0.45 



0.46 



0.4 



0.50 



0.70 

 0.86 



0.88 

 0.80 

 0.81 

 0.83 

 0.80 

 0.83 

 0.85 

 0.82 

 0.87 

 0.81 



0.99 

 1.04 

 1.07 

 0.91 

 1.05 

 1.07 

 1.00 

 1.04 

 1.05 

 1.06 

 1.06 

 1.02 



3.75 

 3.25 

 3.75 

 3.00 

 3.27 

 3.35 

 3.15 

 3.00 

 3.40 

 3.00 

 3.25 

 3.10 



3.43 

 3.25 

 2.15 



1.98 

 2.23 

 2.25 

 2.25 

 2.20 

 2.20 

 2.40 

 2.50 

 2.60 



Len;xth of — 



0.31 

 0. 3G 

 0. 33 

 0.32 

 0.3! 

 0.33 

 0.3'l 

 0.20 



0..63 

 0.70 

 0.73 

 0. 72 

 0.70 

 0.68 

 0. S3 

 0.61 



0.59 

 0.47 

 0.53 

 0.50 

 0.50 

 0.51 

 0.51 

 0.51 



Hesperomys (Onychomys) leucogaster, (Maxim.) Baird. 



The Missouri Mouse is moderately abundant in this vicinity. I have, 

 however, thus far had but little success in trapping it; most of the speci- 

 mens secured have been taken by judiciously trained cats, sensible 

 enough in the majority of cases not to mutilate their victims. Ten of 

 these Mice have been so captured, seven of which have been preserved, 

 and three were found to be too badly damaged to serve any useful pur- 

 pose. Of late, I have succeeded in capturing this mouse by use of the 

 "eagle's claw" trap. 



On the eastern slope of the small plateau on which the post is situated 

 are several old "shacks", constructed one-half or two-thirds underground, 

 and inhabited by Indians; it is in and about these caves that the Mis- 

 souri Mouse has been taken. What special attraction there may be in 



