Microtus breweri (Baird, 1858) . Mammals, in Repts. Expl. Surv ...., 8(1):525.
REVIEWED BY: R. H. Tamarin (RHT).
TYPE LOCALITY: U.S.A., Massachusetts, Muskeget Isl .
DISTRIBUTION: Muskeget Isl. (Massachusetts, U.S.A.).
COMMENT: Subgenus Microtus; related to pennsylvanicus of the adjacent mainland; treated as a full species in a review by Tamarin and Kunz, 1974, Mamm. Species, 45:1-3, but may be conspecific; see Fivush et al., 1975, J. Mammal., 56:272-273.