Jan. 7. 4 mi. S. Gadsden, 120', Yuma Co., Ariz. Pan traps and skinned a.m. P.M. set line of 24 rat traps for neotoma. There are numerous nests all through the mesquite thickets. All nests seen were on the ground; none in trees. Skinned P.M. Jan. 8. Rat traps yielded 1 serognathus, 2 beromyines, + 5 neotoma alligula. Only 2 of the latter were saveable, the others having broken skulls. These rats are so large that even large rat traps are Too small for the striker to miss the skull. One of the broken-skulled rats weighed 320 grams. Crums were used instead of the usual walnut bait, and seemed about as effective. Skinned a.m. In P.M. set about 45 mouse and 6 rat traps in the mesa for dipodomys. The sign was very poor. There were numerous burrows, but only about 5 or 6 showed fresh sign. Jan. 9. Pan traps a.m. 5 dipos deserti and only 1 Q. meriamii This is the first locality we trapped where deserti outnumbered meriamii. Total catch was 12 deserti and 5 meriamii. Skinned a.m. and part of P.M. Spent rest of day breaking camp for early start tomorrow. Jan. 10. Broke camp. Drove to Yuma. Then to Antevae Canyon (State Highway 78, turn off 22 mi. NW Brawley). Very lush desert. Much Yuera and Cholla. Grass and moss over extensive areas. Roads covered