Megadontomys thomasi (Merriam, 1898) . Proc. Biol. Soc. Washington, 12:116.

TYPE LOCALITY: Mexico, Guerrero, mountains near Chilpancingo, 9700 ft .

DISTRIBUTION: High Sierra Madre del Sur of Guerrero, Mexico.

COMMENTS: Formerly encompassed cryophilus and nelsoni as subspecies (Musser, 1964); see above accounts.