JESimpson,1938. 47 Sonora,Sonora. April 8,1938,continued. game-warden of the Republic) game-warden, Señor Tomas Moreno, again, and then the custom-officials at the border. The latter agreed to Dr. Benson's taking our study-skins over the line to mail to the Museum from Aho, Arizona. Picked up boxes to pack rats in, and our laundry from Señor Quiroz's maid, Lucy. Drove out to the flour-mill (owned by Señor Quiroz; but now dismantled) where we made camp: 1400±ft., 1 mile Sonora, Sonora April 9, 1938 Packed specimens with cotton and paper-tubes from magazine pages. Dr. Benson drove the truck over the border in the morning and returned in the early afternoon, with the rear motor-mountings broken; these mountings had been repaired on an- other trip in Mexico by a Mexican blacksmith — competent mechanics are very rare in the Republic. In the meantime Señor Delgadillo and I stayed in camp writing notes, setting rat traps, etc. Señor Delgadillo caught a round-tailed ground squirrel (JES 87/38) in mesquite area. I shot a lizard in the sand and sage(139). Set out 123 mouse-traps: 50 in dense mesquite of flood-banks of Río Sonora; 50 in rocky hills where there is much saquero, papayo, paloverde, creosote, and some cholla; 23 in the level sand (and sage) bordered by dense mesquite