deeper into the mine. It was along the walls of this tunnel that I caught two Pteronotus and one Natalus. Sometimes Mormoops were flying by us so abundantly that our progress was impeded. As we reached the farther end of the mine Pteronotus were more common, at one place over a small slope I caught many with my butterfly net. It was damp in the back part of the mine but we found it well drained. The mine was alive with cockroaches. Natalus Nos. 12201, 12202, and 12209 were taken. Pteronotus Nos. 12203, 12204, 12205, 12207, 12208, 12210, 12212 to 12219 inclusive were taken. Pteronotus davyi, Nos. 12206, and 12211 were taken. Clear morning cloudy in afternoon. 6:30 A.M. & 60° F.; 12 N. 80° F.; 12 N. 117° F. in sun. December 20, 1986 - The forenoon was spent preparing specimens and packing and during the afternoon we rode back to Dibollado.