C. Koford Caluromys derbianus November 11, 1956 Barro Colorado Is., Canal Zone Boconego found one near banana trees & brought it in in net. Very fierce biting, always attacked rather than retreating, but with bare weak. Cut off a right rear toe Q I // & released in p.m. in fruit tree. It stayed 10 minutes. Then went to tip another branch & jumped 7 feet down to grassy ground. Ad. or testes about 9 mm. drain. coat in blue-gray coat. Tail about 15" distal half white. Weighed 295 grms. When grabbed gave repeated shrill squeals. In tree climbed up. Did not seem to seek, dark retreat. Took photo in tree. December 26, 1956. Had long good look at one in lower branches of Cecropia just S. of Chapman House about 8 p.m. A Didelphis in tree at same time. Eyeskin of both yellowish white. January 9, 1957. About 7 p.m., saw one (+ 2 Didelphis marsupialis) in balza to S. of Chapman House. Climbed smoothly up branches, January 12, 1957. In evening had several good views at 6 ft. tree 20 ft. in lower part of balza.