Microdipodops megacephalus Merriam, 1891 . N. Am. Fauna, 5:116.

TYPE LOCALITY: USA, Nevada, Elko Co., Halleck .

DISTRIBUTION: SE Oregon, S Idaho, NE and EC California, N and C Nevada, and WC Utah (USA).

SYNONYMS: albiventer Hall and Durrant, ambiguus Hall, atrirelictus Hafner, californicus Merriam, leucotis Hall and Durrant, médius Hall, nasutus Hall, nexus Hall, oregonus Merriam, paululus Hall and Durrant, polionotus Grinnell, sabulonis Hall.

COMMENTS: Reviewed by O'Farrell and Blaustein (1974a, Mammalian Species, 46). The suggestion by Hall (1941:380-382) of hybridization between megacephalus and pallidus was discounted by Hafner et al. (1979). Also, Hall's suggestion (1981:560) that leucotis may warrant specific status is not supported (see Hafner and Hafner, 1983).