_Diagnosis._--Size medium to small for the species; measurements of type and two topotypes are: total length, 107, 108, 117; tail, 45, 45, 45; hind foot, 12.1, 12.3, 12.5. Color dark brownish or fuscous in summer pelage; winter pelage unknown.
_Comparison._--Resembles _S. v. obscurus_ in size; darker than _obscurus_ in summer pelage; cranium slightly higher and top more nearly flat; larger and darker in summer pelage than the new subspecies from central Montana.
_Remarks._--In their description of this subspecies Anderson and Rand pointed out that specimens from the type locality and from central Saskatchewan represent the dark extreme in a color cline which begins in south-central British Columbia with "pale, brownish-tinged animals." These authors referred shrews from Cypress Hills, southwestern Saskatchewan and southeastern Alberta to _S. o. soperi_, although they noted that these specimens, taken by themselves, are not strikingly different from _S. o. obscurus_ from the Rocky Mountains. The specimens from the Cypress Hills were included in _soperi_ because the authors felt that the subspecific boundary should be drawn "where specimens average about half way between the extremes (of the cline) in characters."
It is true, as Anderson and Rand say, that the shrews from Cypress Hills are hardly separable from those from, say, Waterton Lakes Park. The specimens from the Cypress Hills are noticeably different from specimens from the Okanagan area, but some of the latter, in my opinion may represent intergrades between _S. v. obscurus_ and the more reddish _S. v. vagrans_ and are not, at any rate, typical _obscurus_. In view of the similarity of shrews from Cypress Hills to typical _S. v. obscurus_ and since the Cypress Hills are much nearer to the range of _S. v. obscurus_ than to the record-stations of occurrence in central Saskatchewan and Manitoba, I have chosen to restrict the name _soperi_ to shrews from these latter two localities. Seemingly _S. vagrans_ is absent from the plains separating the Cypress Hills from the Rocky Mountains and from Riding Mountain National Park.
_Marginal records._--SASKATCHEWAN: Prince Albert National Park, 1700 ft. (Anderson and Rand, 1945:48). MANITOBA: Riding Mountain National Park, 2-1/2 mi. NW Audy Lake (ibid.).