Murray 1949 Journal June 17 W end Ilano de Hiney, 50' ft., Baja Calif. In the live traps caught 1♂, 1♀ Dipodomys meriamii and 1♂, 1♀ young. 2♀ Dipodomys agilis, 2♂, 1♀ Perognathus baileyi and 3♂, 1♀ baileyi young. Also 1 young Perognathus arenarius. Released all young ones. The rat traps had 2♂ Perognathus baileyi. The 20 traps which were empty at 9:15 M last night turned up with 4 rats and 1 mouse. Almost every one of the traps had been visited by mice, rats or both. In most cases the seeds had been eaten out of the front of the trap, others they apparently were afraid to touch. With all the tracks showing so clearly it was possible to get some idea of their nocturnal activity. Under bushes, and especially cholla there were many tracks, of ten an almost solid mass of them. Out in the open there was less movement, but most of the space had been covered by one or another to some extent. After finishing up the specimens we went on to Pozo Grande, where we camped beside the pond as before. This time there was not the great crowd of Myotis yumanensis. Rather, only 4 or 5 appeared late and flew rapidly over the surface. A number of Eptesicus fuscus fed nearly