Sorex obscurus Merriam, N. Amer. Fauna, 10:72, December 31, 1895. (Type from near Timber Creek, altitude 8200 ft., Salmon River Mountains, now Lemhi Mountains, 10 miles west of Junction, Lemhi County, Idaho.)
Specimens examined.—Total 12, as follows: Yukon Territory: McIntyre Creek, 2250 ft., 3 mi. NW Whitehorse, 1; SW end Dezadeash Lake, 2; 1½ mi. S and 3 mi. E Dalton Post, 2500 ft., 1. British Columbia: Stonehouse Creek, 5½ mi. W jct. Stonehouse Creek and Kelsall River, 4; W side Mt. Glave, 4000 ft., 14 mi. S and 2 mi. E Kelsall Lake, 1; Hot Springs, 3 mi. WNW jct. Trout River and Liard River, 1. Alberta: Assineau River, 1920 ft., 10 mi. E and 1 mi. N Kinuso, 2.
Remarks.—Some of the shrews taken in extreme southwestern Yukon Territory (1½ miles south and 3 miles east of Dalton Post) and in extreme northwestern British Columbia (Stonehouse Creek and Mt. Glave) show evidence of intergradation with the coastal subspecies, S. o. alascensis, in length of hind foot. These individuals have a long hind foot (14 and 15); the hind feet of specimens from the other localities listed measure 13 and 14.
Alcorn, like Rand (1944:35), found the dusky shrew to be less common than the cinereous shrew; both were taken in the same trap lines. The dusky shrew was taken at a higher altitude (4000 feet, on Mt. Glave) than the cinereous shrew.
Sorex obscurus shumaginensis Merriam
Dusky Shrew
Sorex alascensis shumaginensis Merriam, Proc. Washington Acad. Sci., 2:18, March 14, 1900. (Type from Popof Island, Shumagin Islands, Alaska.)
Sorex obscurus shumaginensis J. A. Allen, Bull. Amer. Mus. Nat. Hist, 16:228, July 12, 1902.
Specimens examined.—Total 3, as follows: Alaska: 1 mi. NE Anchorage, 100 ft., 1; Glenn Highway, 6 mi. WSW Snowshoe Lake, 2.
Remarks.—These three shrews, in comparison with those referred to S. o. obscurus, are paler, and the one complete skull has a slightly higher braincase. All of the specimens were obtained in grassy areas adjacent to the roadway.