Megadontomys cryophilus (Musser, 1964) . Occas. Pap. Mus. Zool., Univ. Michigan, 636:13.

TYPE LOCALITY: Mexico, Oaxaca, Distrito de Ixtlan, 13 mi NE Llano de las Flores, south slope Cerro Pelon, 9200 ft .

DISTRIBUTION: Sierra de Juarez, NC Oaxaca, Mexico.

COMMENTS: Named as a subspecies of Peromyscus thomasi . Citing morphological traits and genetic differentiation reported by Werbitsky and Kilpatrick (1987), Carleton (1989) arranged cryophilus as a species.