Ochrotomys Osgood, 1909 . N. Am. Fauna, 28:222.

TYPE SPECIES: Arvicola nuttalli Harlan, 1832 .

COMMENTS: Although diagnosed as a subgenus of Peromyscus, the distant kinship and generic segregation of Ochrotomys have been repeatedly sustained (Blair, 1942; Carleton, 1980; Hooper and Musser, 1964b; Patton and Hsu, 1967). A peromyscine, but this conventional placement has been questioned (see Engstrom and Bickham, 1982; Carleton, 1989:115).