7 mi. n. e. Fort Yuma, 200', Imperial Co., Calif. Dec. 23. Hundred yards in an irrigation ditch bordered by arrowweed (Pluchea sericea) and introduced cane and Bermuda grass. It is in the cane-Bermuda grass asso- ciation that Sigmodon hispidus is found. Much of this vegetation has been cleared or burned, and upon our arrival we met a crew engaged in clearing the irrigation ditch banks. A species of Baccharis is quite common here, as is Fremont cottonwood (To- pulus fremontii), screwbean mesquite (Prosopis alubescens) also noted. Traps were set in some cane and arrowweed. Skinned after dark. Dec. 24. Combined trap lines produced 7 Sigmodon, 2 Peromyscus, several house mice, Reithrodonto- mys megalotis, and 2 Perognathus penicillatus. Skinned a. m. Drove rained very heavily during morning and early p. m. Cleared and we drove to Yuma. On our return contacted George Berry, who lives 1 mi. from Bard. On our arrival at camp Dec. 23 we noticed 2 dead gophers, and were told by the bamboo- cutters that they were trapped by Berry. He seems rather intelligent, lets out 50-80 traps day and catches 15-30 gophers daily. Also sets muskrats. Told us the gophers caused