JESimpson, 1938. p.3. Dipodomys merriami (continued). 50±ft., Cerro La Cholla, 6 mi. wnw Punta Peñasca, Sonora. April 6, 1938, continued. saved; much of this material consisted of small, white, onion-like tubers which have been found once or twice before in the pouches. These tubers may have come from the many small pits found dug in the sand dunes along my trap-lining. 100±ft., Cerro Prieto, 6 mi. nw Punta Peñasca, Sonora. April 7, 1938. 3♂'s and 1♀ caught among creosote-like brush in sand at edge of dark lava hill. Cheek-pouch contents were saved. 350±ft., Batamote, Rio Sonorita, 39 mi. wsw Sonorita, Sonora. April 8, 1938. 3♂'s and 2♀'s taken among mesquite and creosote in sand along banks of river. Total for party was 13 (7♂'s; 6♀). Cheek-pouch contents were saved. 1400±ft., 1 mi. ne. Sonorita, Sonora. April 10, 1938. Only 1♂ and 1♀ caught from 50 mouse- traps placed in dense mesquite near Rio Sonorita. The dense mesquite provide food and over-head cover, but the lack of ground cover (due to over-grazing and the density of mesquite) and periodic flooding probably account for scarcity of rodents. continued.