The pigmy woodrat, Neotoma goldmani Merriam, the smallest known member of the genus, inhabits rocky areas in the elevated desert regions of the northern part of the Mexican Plateau (Mesa del Norte). Goldman (N. Amer. Fauna, 31:82, October 10, 1910) had for study ten specimens from two localities in Coahuila. Since his report, Dalquest (Louisiana State Univ. Studies, Biol. Sci. Ser. No. 1:162, December 28, 1953) extended the known distribution of this species approximately 225 miles southward int