JESimpson 1938 2300 ft., 1 mi. S. Moctezuma, Sonora. May 26, 1938, continued (jv. 444 as skull only); this gopher take between edge of wheatfield and irrigation ditch. The river-bottom (Rio Moctezuma) land is here planted to wheat, melons, and sorghum, mainly, to the base of the east cliff-bank of dark lava (where mouse and rat traps set) and cut by many irrigation ditches which served to flood and ditch- irrigate the fields. An old (still in use) sorghum mill stands at the base of the lava-conglomerate cliff. Probably the lava did not cross the river in its flow as the cliff shows only courting and slides of dark lava whereas the the mesa-top is mostly lava rock and very dark brown (lava?) soil with some few patches of conglomerate near the edge of the bank-cliff. Thick brush grows on the cliff-slope and parts of the mesa-top where, however, it is mostly less dense brush (1e, 1-4 bushes/10sq ft). Set 50 live-traps from sorghum mill along irrig- ation ditch between wheatfields and base of lava cliff; set 11 rat-traps in black lava rocks on slope of cliff along same trap-line as last-night's rat-line on which no rats taken but much sign apparent; set 93 mousetraps on mesa-top in black-lava rocks and dark brown soil; reset gopher traps. May 27, 1938. In the live traps set at edge of wheatfields caught nothing; in the rat-traps in black lava rocks on cliff- slope caught only one Peromyscus eremicus (not saved);