Mayhew 1959 Journal 41. April 25 Colorado Desert Imperial Co., Calif. We arose at 0640 and f[illegible]ed breakf[ast]. We drove to stations I & II in the dunes at 0715 and obtained our soil samples. Then we drove to an area west of the large irrigation canal at the western edge of the dunes. Here we collected 1 Phrynosoma m'calli (?). Then we returned to the dune area (1030) where we caught the following animals: Uma notata - 8 ad. ♂, 4 adult ♀, 2 immature ♂, and 5 immature ♀; Urosaurus graciosa - 4 adult ♂, 1 adult ♀; Callisaurus draconoides - 2 adult ♂, 3 immature (?) ♀; Crotaphytus w[illegible]zeni - 2 adult ♀; Mastigophis flagellum - 1 immature (sex unknown). We released 3 other Uma notata ♂, and killed one Crotalus cerastes that was coiled at the edge of an Eriogonum sp. We returned to the car at 1430 even though adult Uma notata were still quite active (The sky had been completely overcast all day). At this time, the air temp.(30") was 29.8°C., air temp.(1cm) was 31.0°C., and soil surface temp was 41.2°. The relative humidity was 30%. A total of 33 animals of 6 genera and 6 species were kept from this morning's activity, and 14 animals of 1 genus and species were