Peromyscus m. sonoriensis Engler 1936 July 4. 2 1/2 mi. E Flanigan, 4200 ft., Washoe Co., Nev. Taken in the sandy areas of this locality where the bushes are more widely scattered. 6 specimens were taken representing 6.6% of the total catch. July 7 Smoke Cr, 3900 ft, 2 mi. E Calif. line Washoe Co., Nev. 3 taken on sandy, artemisia covered bank bordering stream. Perognathus parvus taken here also. July 10 17 mi. W Dephole, 4800 ft, Washoe Co., Nev. 3 indi- viduals taken from a trap line of 41 traps. The ground was very rocky with scattered, low, artemisia bushes on a hill which were dotted with juniper trees. Taken in association with P. crinitus & P. truei, Perognathus parvus & Reithrodontomy's megalotis. July 12 Rock Cr, 6000 ft, Granite Mt., Washoe Co., Nev. 1 specimen taken on top of steep hill near pile of granite boulders. The ground around the rocks was coarsely gravelly from the decomposing granite. Along N br. at an altitude of 5200 ft, 6 specimens were taken from the rocky hill bordering the stream. Found in association here with Perognathus parvus the soil was dry & dusty.