M. Koford 1951 Myotis nigricans Feb. 23 Laboratory Buildings, Barro Colorado Island These bats were hanging on the outside of several of the buildings in broad daylight. On the Barbour and Zetek houses they were all single, mostly in corners formed where the walls, roof, & rafters met. We collected 4 of these - all ??. On the Kodak house they were clustered in groups of 2 to 10 or more. On disturbance, they flew a little more readily than the single ones. We caught 3 - all ??. Feb. 24 This morning Carl caught 3 more - 2 ?? single as before, and a ?, one of several clustered on the Kodak house. In the dark attic of the Chapman house we found large numbers in clusters. All we looked at were ?? except for one ? and two Molossus (10, 1?). All the ?? were pregnant.