Synaptomys borealis (Richardson, 1828) . Zool. J., 3:517.

TYPE LOCALITY: Canada, Mackenzie, Great Bear Lake, Ft. Franklin .

DISTRIBUTION: S.E. and C. Alaska (U.S.A.), to S. shore of Hudson Bay to Labrador (Canada), south to N. Minnesota, Montana, and Washington; isolated populations from S.E. Quebec to N. New Hampshire (U.S.A.).

COMMENT: Subgenus Mictomys; revised by Howell, 1927, N. Am. Fauna, 50:1 -38. Koenigswald and Martin, in press, Bull. Carnegie Mus. Nat. Hist., considered Mictomys a distinct genus; two extinct subgenera are also referable to Mictomys .

ISIS NUMBER: 5301410008086001001.