Quest 1946 Pipistrellus hesperus 4 May 23 E. Carragita, 1400ft, 5 mi N. Santiago, Baja California. Specimen flew into wires stretched one inch above water surface at same moment as two Eptesicus fuscus. May 27 Same location. One female (#265) with 2 embs of 9mm cought at dark last night as it flew over water tanks 100 yards west of camp. The Pipistrellus seem attracted to the swinging net, swinging around and following it in its course very often. The Pipistrellus are very common here, they being seen in numbers around the large gran- ite boulders of the hillside, and along the roadway and garden near camp. Tevis and Murray have netted many over the water tanks on the hillside at dusk and darks. May 28 Same location. 8? netted here last night over the upper water tanks between 7:30 and 9:30. No other bats were caught by myself, but Tevis caught one Corynorhinus and a Myotis californicus on the opposite side of the tank in the same interval. Each time a Pipistrellus was cought, several others were noted in the vicinity, they seeming to come in associated groups. May 29 Same location. One shot 6:45 P.M. yesterday as it was flying over cornfield next to camp. (#269)