A.C.BIEBEL 1960 Pernognathus penicillatus 7 mi. (by road) ESE Barstow, San Bernardino Co., Calif. 1 MAY 16 taken in 34 Sherman traps 3 @20 mession, made up rest of catch. Sandy with scattered small bushes, no "mus-like" odor noticed for this species. 3 animals were saved as study skins (one as comp skin only). There seems to be a large size diff. in mature animals, both between &/or between diff. age(?) animals of same sex. For example: (both from Barstow mtn S.E. San Bern.) #1850 263 -> TIB 478mm, CAIS+ WEIGHED 27.0gm #185) " " Tib 479mm, " " only 16.1gm. and a- 13.2gm F (#49 262.) which I THOT must be immature before skinning, turned out to have 9" old" pleceum scars. This size diff. seems to parallel the situation found in Thorovys.