Seib, R. 1984 Chilpancingo to Acapulco, Guerrero, Mexico 6 Nov. pieces of net over roost entrances. Drove into Acapulco late and stayed at a lodge called The Impala. Acapulco, Guerrero, Mexico 7 Nov Woke and had breakfast. The objective of the day was to net Balantiopteryx at the rocks above Las Brisas, about 2km E of the Naval Base. This place is a locality out of Bernardo Villa's "Mariposas de Mexico" So we decided to partake of the beautiful facilities at The Princess and did so until late afternoon when we actually received the boat. At this point we went to the rock and set up nets. We put a piece of net over a small rock opening where we saw bats roosting and flying in direct after- noon sunlight. We also set up two nets near a major common roost - these caught nothing but the first piece of net caught 5 Balantiopteryx picta. Those were all FF and not useful, having not the wing sac. Sexes of this species are known to roost separately at certain times, such as summer.