Chattin, J. 1940 Itinerary Dec. 28 (cont'd) 7 mi. NE Fort Yuma, 200 ft., Imperial Co., Calif. Fort Yuma and at 2 mi. NW of Patholes were taken up. Patch from line 2 mi. NW Patholes contained 1 Neotoma lepida, 1 Dipodomys merriami and 2 Peromyscus.. Line at 7 mi. NE Fort Yuma contained 1 Spermophilus (pres. J. Davis) and 3 Reithrodontomys. In p.m. a series of Thomomys trapped by George Barry at 1 mi. N Bard 200 ft., were skinned. 20 mouse traps were set out in arrowweed thickets on alkali flat near camp. Dec. 29 a.m. - Trap line of 20 traps contained 3 Perognathus penicillatus and 2 Peromyscus maniculatus. During the night a moderately heavy rain fell. In early p.m. 4 Ondatra obtained from L. Retherford, a trapper working along the river bottom, were prepared. In late p.m. and during the night more rain fell making it im- pssible to set out a trap line. Dec. 30 a.m. 4 more Ondatra were obtained from the trapper. All of these were taken in line of 40-50 traps at 21/2 mi. NE Fort Yuma, 200 ft. Camp was moved in p.m. to locality at 10 mi. SE Fortuna Mine, 300 ft., Yuma Co., Ariz. Camp was set up about dark along the edge of a wash at the base of W side of Lila Mtne. - A line of about 40 traps was set out after dark in the rocks, then threw