Murray 1948 Natalus mexicanus May 24 Las Cerevas, 23°34'N, 109°39'W, Baja Calif. Found a large cave here, washed out of the high sandstone cliff along the river bed. There were two main chambers, extending back about 120 feet in all. At the rear there was a crevice which broadened out into space for many Natalus hanging close together. We caught a total of 53, probably close to 2/3 of the number present. Several were a bright orange color. On the wall and celing were very many Myotis velifer, and a few Macrothus californicus on the top. Also on the ceiling, grouped together, were several more Natalus. We estimated the total number at very roughly 15,000 of all the species. (See journal) June 7 La Tenaja, 5 mi SE Punta Gasparina, Baja Calif. Went up the Arroyo de la Tenaja to this place, a small muddy pool about 2 x 6 feet and fed by another smaller pool close to it. The Natalus arrived when almost dark — a few times 2 or 3 together, usually just 1 at a time. One would fly around for a few minutes and leave, then soon it or another would return. Almost always they flew very low, within 2 or 3 inches of the ground, and very swiftly and elusively. Often they wound in and out of the bushes.