Bants, R.C. 1955 28-31 Oct. cont'd. 6. On the evening of 29 Oct. all traps were moved but 1 mus. sp., which was lost. 5 rat traps set in Privo Valley, Contra Costa Co., where we had seen a colony of Beechy Ground Squirrel. 24 mus. sp. set in wooded ravine + bushy field 3 1/2 mi. N. Onida 700+ ft. near Hampton Rd. (?) in Contra Costa Co. All sets made just before dark. Sun. A.M. had 1 ♂ Peromyscus truei and 1 ♂ Perognathus californicus, no ground squirrels. Put these 2 mus as RCB 17+18. In P.M. moved rat traps to area of mus. sp., near 2 wood rat houses. Mon. A.M. (31 Oct.) had 1 ♂ Reithrodontomys megalois (RCB 19). 2 rat traps spring, 1 closely.