Chattin J. 1941 Itinerary 16-mv. SE Fortuna Mine, 300 ft., Yuma Co., Ariz. 1 rat trap was lost in rocks being carried away by some carnivore. Catch consisted of 13 Dipodomys deserti and 7 Dipodomys merriami. (1 of the deserti caught in a steel trap). Catch was skinned during the day and in p.m. 8 sets were made in fresh pocket gopher workings in small sand dune at the base of the Butler Mts. Jan 3 a.m. Gopher sets were taken up and 1 Thomomys was taken. Camp was then moved. On road out to main highway a stop was made at Fortuna Mine, 700 ft., Yuma Co., Ariz., where 20+ Macrotus were taken in an old mine drift. From here we traveled on to Yuma and then down to the Mexican Boundary at San Luis. Camp was pitched a short distance from the Custom house and 30 mouse traps were set out in sandy soil on creosote bush mesa, Jan. 4 a.m. Traps were picked up. Catch consisted of 2 D. deserti and 1 D. merriami. During day we cvent into Yuma for car repairs and then scouted around for camp site near the border. Camp was finally located near the edge of the mesa in the bottomlands of the river at 4 mi. S. Gadsden, 120 ft., Yuma Co., Ariz. In the afternoon a line of 70 mouse traps and 5 rat traps was set out along a ditch bank