Murray 1948 58 Journal Mayo Pozo Grande, 25°46'N, 112°02'W, Baja Calif. dead cardons and brush. Coming down the canyon saw 3 Citellus atricapillus. After the long descent we finally emerged onto the Magdalena plain. Here was soft brown sand on which grew cardon, cholla, ocotillo and pitahaya all with considerable orchilla on them. Came to Pozo Grande where we ate at a ranch house and then camped by the nearby pond. This was about 80 x 20 yds, bordered on one side by a few mesquites. Heavy use by cattle apparently precluded any more growth. Just before dusk the air was filled with violet-green swallow and a few killdeers. Then bats began to appear, seeming to pour out of a small rocky ridge along one bank. I netted 3 Mystis yumanensis by standing on a rock by the water, and the others shot some. These tended to stick rather close to the water and often close to the bank sometimes flying into the bushes. A little later, larger bats appeared, among which Eptesicus fuscus was represented. We tried to hunt after dark by the light of truck headlights but to no avail. The