Quast 1948 Pteronathus baileyi 2 June 17 Went Llano de Hiley, 50 ft. Baja California set in dry lake bottom. The juvenile and immature specimens were released, leaving the series # 363-369 incl. Of the two female specimens, one had 2 embryos on the right side of 7mm, and the other none. This species was caught in the lake-bottom proper and also around small hillocks of sand intermediate between it and the sand dunes. Growing in the lake bottom in a fairly even cover and on the small sand hillocks as several kinds of very short bushes from 3 inches to a foot high. In hillocks beneath these bushes, Pteronathus baileyi burrows are common and their tracks are every- where in the more sandy places. When many of the specimens were released from the live traps they continued to stay around camp and became at ease around the place, eating and sitting under the table and around our feet with no apparent fear at our presence. Several specimens that were almost too cold to move this morning were covered with a piece of paper and showed a great attraction for it later when they would move to follow it when we changed its position. Minimum temperature last night was 53° F. Several very young specimens were caught, still having very fine hair with their pink skin showing through. June 19 San Jorge, 5 ft., 25°44'N, 112°02'SW, Baja California Two caught last night, one female in Museum.