JESimpson, 1938. 2100+ ft., 45 mi. n. Hermosillo, Sonora. May 15, 1938 Caught in mousetraps and rat-traps set on tan-soil among grass, Palo fierro, bara blanca, and mesquite: 13 Perognathus penicillatus (o> and 4 ?: put up o> 372-75 and & 376-379), 1 Onychomys torridus no emb. (o>380), 3 Dipodomys spectabilis (2o>and 1 ?: o>381; & 382), no emb. 5 Dipodomys merriami (2? and 3o>: o>383-84). Cheek- pouch contents of pocket-mice and kangaroo rats saved. Put up Mountain Towhee (Pipilo fuscus mesoleucus) (o>385) shot yesterday, May 14, 1938. Broke camp and drove thru Hermosillo to 925+ ft., 1 mi. SW. Hermosillo, Sonora. Made camp here at Rancho La Regional with permission of operators to trap. While Dr. Benson and Señor Delgadillo set out gopher traps, I made a battrap at a 35 ft-diameter water-pond - using the Borell method by stretching wires close to the surface. The trap was entirely twenty satisfactory; however, there were very few bats. A dozen or so pipistrels skimmed the water, and three of them ticked the wire - none falling. Later two or three larger bats appeared; one was taken, a Mexican free-tail. This small catch is no reflection upon the effectiveness of the Borell bat-trap, but that the region has many potential watering places for bats, eg, irrigation ditches, ponds, and the Rio Sonora. (cf., Costa Rica Ranch, May 1-9, 1938 pp.66-70. May 16, 1938. Put up my bat, Tadarida mexicana (o>386). Then May 15, 1938.