Sorex hydrodromus Dobson, 1889. Ann. Mag. Nat. Hist., ser. 6, 4:373.

TYPE LOCALITY: USA, Alaska, "Unalaska Islands, Aleutian Islands" (probably in error, presumably from St. Paul, Pribilof Isis).

DISTRIBUTION: Known only from St. Paul in the Pribilof Isis, Bering Sea.

SYNONYMS: pribilofensis.

COMMENTS: Subgenus Otisorex. There is some discrepancy in the literature on the correct name for this species. Dobson's hydrodromus has priority, but because of an apparently incorrect type locality information and further inconsistencies in the original description, Hoffmann and Peterson (1967) proposed to suppress hydrodromus in favour of pribilofensis Merriam, 1895, a suggestion followed by van Zyll de Jong (1991 b). However, Yudin (1969), Baranova et al. (1981), Hall (1981), Junge and Hoffmann (1981), and Honacki et al. (1982) retained hydrodromus, while Gureev (1979) listed both hydrodromus and pribilofensis as species. As the holotype of hydrodromus still exists in the St. Petersburg Museum, there seems to be no reason for not following the rule of priority.