Quast 1948 Natalus mexicanus May 24 Las Cuevas, 23°34'N, 109°39'W, Baja California Approx. 40 specimens taken from a cave near town this morning. The Natalus were hanging in the first cave visited (for description see journal pg 86). Hanging nearby were several hundred Myotis velifer. The males of this species have a large muscle - like gland on top of the skull rostrum. It is so large that it changes the appearance of the skinned head considerably and cannot help but be noticed. The females have only a small ligament or fascia in the corresponding position. May 31 El Chono, 800±ft, 2mi W. Agua Caliente, Cape District, Baja Calif. About 20 of this species brought into camp yesterday afternoon by boys who had caught them in an irrigation sited tunnel. Dr. Benes put up several specimens. Color variation of pelage from cream-white to orange in different individuals evidently does not depend upon sex. Both ♂ and ♀ individuals were found in both extremes. June 7 Punta Gasparino, 10±ft, 23°16'N, 110°9'W, Baja California One netted by Murray at dusk at a ranch near her. Area had open water available. The bat was said to have been flying very close to the ground and in a very erratic fashion. Netted at dusk.