Peromyscus difficilis (J. A. Allen, 1891) . Bull. Am. Mus. Nat. Hist., 3:298.

TYPE LOCALITY: Mexico, Zacatecas, Sierra de Valparaiso .

DISTRIBUTION: N. Colorado (U.S.A.) to Oaxaca (Mexico).

COMMENT: Includes nasutus; see Hoffmeister and de la Torre, 1961, J. Mammal., 42:1- 13, Hooper, 1968, in King, ed., The Biology of Peromyscus (Rodentia), p. 27, and Hall, 1981:706. Reviewed by Diersing, 1976, Proc. Biol. Soc. Wash., 89:451-466. May comprise two distinct species (WC).

ISIS NUMBER: 5301410008039013001.