_Range._--Southwestern Alaska from Seward Peninsula southeasterly to western part of Kenai Peninsula and southwesterly to the southwestern end of the Alaskan Peninsula. _Diagnosis._--Size medium to small for the species; average and extreme measurements of 6 specimens from King Cove, Alaska, are: total length, 112.7 (107-118); tail, 48.3 (45-52); hind foot, 13.8 (13-14). Tending toward the development of a tricolor pattern, the back darkest, the sides buffy, and the venter paler. _Comparisons._--Paler and more definitely tricolored than _S. v. obscurus_; also with relatively shorter palate, narrower rostrum and smaller teeth. For comparison with _S. v. alascensis_ see account of that subspecies. _Remarks._--_S. v. shumaginensis_ occurs together with _Sorex cinereus_ over much of southwestern Alaska. Part of the range of _shumaginensis_ falls within the tundra of the Arctic Life-zone. This may be a partial explanation of the tricolored pattern of the animal. _Sorex tundrensis_, _S. cinereus ugyunak_, and _S. cinereus haydeni_, shrews which dwell mostly in treeless areas, are markedly tricolored, or bicolored. _Sorex arcticus_, however, although tricolored, is found in forested areas. _Specimens examined._--Total number, 340. ALASKA: Sawtooth Mts., Nome River, 2 AMNH; Nulato, 5 BS; St. Michaels, 1 BS; Bethel, 7 BS; Aniak, 1 BS; Skeventna River, 1 BS; 6 mi. WSW Snowshoe Lake, 1 KU; 1 mi. NE Anchorage, 1 KU; Tyonek River, 48 BS; Hope, 15 BS; Hope, Mts. near, 13 BS; Moose Camp, 3 AMNH; Kenai Peninsula, 24 AMNH; Kakwok River, 80 mi. up, 1 BS; Kakhtul River, 5 BS; Kakwok, 3 BS; Goodnews Bay, 1 BS; Lake Aleknagik, 6 BS; Nushagak River, 25 mi. above Nushagak, 1 BS; Dillingham, 1 BS; Nushagak Village, 15 BS; Homer, 1 AMNH; Kenai Mts., 37 AMNH; Seldovia, 24 AMNH; Barabor, 1 AMNH; Caribou Camp, 7 AMNH; Ugagik River, 3 BS; Becharof Lake, 8 BS; Cold Bay, 14 BS; Kanatak, Portgage Bay, 4 BS; Chignik, 6 BS; Moller Bay, 1 BS; Alaska Peninsula, near Popof Island, 6 AMNH; Frosty Peak, 15 BS; Morzhovoi Bay, 7 BS; Ungu Island, 3 BS; Sand Point, Popof Island, 45 AMNH; Popof Island, 3 BS. _Marginal Records._--ALASKA: Nome River; Nulato; Kuskokwim River, 200 mi. above Bethel, Crooked Creek (Jackson, 1928:126); 6 mi. WSW Snowshoe Lake; Seldovia; mts. near Hope; Morhzovoi Bay; thence along coast to St. Michael. =Sorex vagrans obscurus= Merriam _Sorex vagrans similis_ Merriam, N. Amer. Fauna, 5:34, July 31, 1891, _nec. S. similis_ Hensel, Zeitschr. der Deutsch. Geolog. Gesellsch., 7:459, 1855 (= _Neomys similis_). _Sorex obscurus_ Merriam, N. Amer. Fauna, 10:72, December 31, 1895, new name for _Sorex vagrans similis_ Merriam. _Sorex obscurus obscurus_, Miller, Bull. U. S. Nat. Mus., 79:15, December 31, 1912.