lights, a butterfly net, and a sash to put the bats in. There were perhaps 30 vampires (Desmodus rotundus) in the tunnels. We collected Nos. 12050, 12051, 12052, 12053, and 12054. Some of the mothers had young cling to them. I observed them only on the ventral side. These bats have a strong vitality, and we found it very difficult to kill them by pressing in on their hearts. In the mist they hopped around like so many monkeys, always trying to get out of sight into a crevice or behind a ledge. There were about 70 Micronycteris, and as best we could discover only one escaped. We collected Nos. 12044, 12045, 12046, 12047, 12048, and 12049. They hanged head down and from the roof of the tunnel, their sharp claws clinging to projecting rocks and roots. The ears and faced of these little bats twitched nervously when the light