Microdipodops Merriam, 1891 . N. Am. Fauna, 5:115.

TYPE SPECIES: Microdipodops megacephalus Merriam, 1891 .

COMMENTS: Revised by Hall (1941); also see Hafner et al. (1979). Wood (1935), Hafner (1978), and Hall (1981) considered Microdipodops a member of the subfamily Perognathinae . Hafner (1982), Hafner and Hafner (1983), Wahlert (1985), and Ryan (1989a) summarized evidence for referring the genus to the subfamily Dipodomyinae . A key to species is given by Hall (1981:560).