Mastacophis flagellum 1. Mayhew 1959 Apr. 25 5 mi. W. of Glamis, Imperial Co., Calif. a young o? was captured at 1210 today while it was lying coiled in the sand at the mouth of a hole. This was in the sand dune area (Algodones Dunes) covered with creosote brush scrub. The sky was completely overcast at the time (had been all day); the air temp (30') was 26.5 C., (1cm) was 29.5 C., soil surface temp. was 36.8 C. May 9 3 mi. S.E. of Hesperia, San Bernardino Co., Calif. at 1430 an adult was captured beside a Joshua tree. The weather was quite mild for this time of the year in that area. 1960 Apr. 11 10 mi. E. of Dale Dry Lake, San Bernardino Co., Calif. The largest snake of this species I have ever seen was found DOR this afternoon. It was 5 feet long, and bigger in diameter than any I have seen. 15 mi. E. of Dale Dry Lake, San Bernardino Co., Calif. Another DOR, 45 inches long, was found on the road this afternoon. It was nearly as big in diameter as the one found earlier.