Murray 1948 76 Journal May21 Buena Vista, 25±ft., 23°38'N, 109°41'W, Baja Calif. In the evening, watching for bats, did not see the usual Pipistrelles, and but few of any kind. All flew rather late, almost when dark. Shot 1♂ Myotis velifer. Later we went up to see Massey and his family where they are staying in the school house. There caught 3 Macrotes californicus which flew into one of the rooms at various times May22 Same location This morning we drove to Cerro Agua Amarga, 4 mi to the SE around the shore. Here, with Massey and a couple of Mexicans looked for bat caves which they knew about. This hill is very rocky with much of its surface outcroppings of sandstone and a coarser gravelly sedimentary rock. There were many caverns washed out of the rock. One cave extended back about 35 feet, 20 feet across, and 10 high. It contained many bats - 300 or more, which were all Macrotes californicus except one lone Leptonycteris. We spread nets over the mouth and screened them through to be sure of the species. There was some guano on the floor, and it had been dug out in the past. 18♂ and 12♀ Macrotes were kept as