1775ft, 8 mi. s. San Luis, 34 mi. nw. Caborca, Sonora. April 11, 1938, continued. St. Elena, tho only 2 miles from this camp, is very small, a mining camp (unstable), and not on any map; so the above directions chosen. Set 50 mousetraps and 7 rat-traps along banks of wash and on hillside. April 12, 1938 Caught 7 Perognathus intermedius (♂ 145-8; ♀ 149-51), (cheek-pouch contents saved), 4 Peromyscus eremicus (♂ 152,153; ♀ 154,156), and 1 Nectoma albigula (♂ 155). The trap-line ran thru the typical terrain of this region: hills with rocky surface of tan-brown granite-like rocks (much quartz mixed in) cut with many small arroyos and some larger washes; the vegetation is much heavier (3-4 times or more) than the level desert and is predominantly palo verde and creosote with good representation of saquaros, patayos, ochotillo, nopal, cholla, and barrel-cactus, also many soft succulents and other small forms that I do not know. The creosote, nopal, ochotillo, and a low-growing, unstalked cholla are in bloom. Put up specimens with help from Dr. Benson and Señor Delgadillo before they left to rob a bee-hive which Dr. Benson discovered in the rocks on his trap-line. What little honey there was in the hive was burned when a woodrat nest below the hive caught fire from the smudge-fire. Dr. Benson shot two quail for the table. Set out 50 mousetraps and 7 mousetraps in area adjacent and similar to that of last night.