Crickson 1934 Ammospermophilus l. xericola Tinjias Altas, Yuma Co., Arizona. Jan. 12, 1934. Individual seen scampering away into rocks as I approached. Tinjias Altas, Jan. 15, 1934 10:00 heard scolding; as I approached finally located it 50 ft. as it moved to top of rock well up on side of mountain near tanks; an top of rock sat upright; motionless; finally lost it and could not pick it up again. Species of 13th taken in wash near tanks; one on large rock strewn with debris from mesquite above it; other on opposite side of wash 75 ft. away on debris strewn ground under a mesquite. 2:00 One on floor of canyon among Encelia farinosa burro weed and creosote; scampered to rock, climbed on it sat on haunches, front feet on rock; a quick nervous shake of tail given frequently; followed for 75 ft. before lost went toward rocks at base of mountains. Tinjias Altas, Jan. 16, 1934 Male taken in sand at bottom of small gully under creosote bush. Female taken under shelthing rock, both in canyon along S E facing slope; traps out about two hours; two others had bait removed, but were not sprung, one under Encelia farinosa on flat not touched. Tule Tank, 1250 ft., Yuma Co., Ariz, Jan. 18, 1934 One seen on rock slide above the tank, N E facing slope.