Hooper, 1938 Berkeley, Alameda Co., Calif. July 13, about 5 mi. We drove on east (on road to Livermore) looking for good pocket mouse country (Artemesia and rocks), but found nothing better than that on most exposed slopes north of Diablo Cr. I was mistaken in thinking I had seen Artemesia in a rocky canyon about 5 mi. east of the above camp in with the junipers which are found there. I set 31 traps in a S.W.-facing slope among grass and near or under mountain serbogyry, a dwarf Artemesia? (± 10 in. high) and! A few ground squirrels were seen here and some burrows apparently of Dipodomya. From those traps: 2 Dipodomys h., 1 Peromyscus m., 1 Peromyscus californicus, 1 P. truei. In similar situations but with more traps in dried "gramininae" ± 1½ ft. high from 60 traps Feathers took 1 Perognathus c. and about(!!) 10 P. maniculatus . 14 traps set along the edge of brush (= Adenostema, Canthusa curvata, poison oak, and fallen coulter pine debris) netted 1 Dipodomyx (from holes in sandy ground near brush), 2 Peromyscus californicus. 2 P. truei.