Financial support for this investigation was from (1) a United States Army Medical Research and Development Command grant (DA-MD-49-193-62-G65) to the Entomology Department of the Bernice P. Bishop Museum, and (2) a National Science Foundation grant (2185-4703) to the author, through the Committee on Systematics and Evolutionary Biology of The University of Kansas. I am grateful to many individuals who have helped me in various ways throughout the course of this study. Dr. J. Linsley Gressitt, Chairman of the Entomology Department, Bernice Bishop Museum, allowed me to study specimens collected by his expeditions; Professors E. Raymond Hall and J. Knox Jones, Jr., of the Museum of Natural History and the Department of Zoology, The University of Kansas, offered advice and guidance and constructively reviewed the manuscript. Other persons who have given me assistance and, in some cases, arranged for loans of comparative materials, are: Dr. David H. Johnson, Division of Mammals, United States National Museum; Mr. Hobart M. Van Deusen and Dr. Richard G. Van Gelder, Archbold Expeditions and Department of Mammalogy, American Museum of Natural History; Messrs. Ellis LeG. Troughton and Basil Marlow, Mammal Department, The Australian Museum; Dr. Joseph Curtis Moore, Department of Mammalogy, Field Museum of Natural History; Mr. John Edwards Hill, Mammal Room, British Museum (Natural History); Prof. William B. Davis, Department of Zoology, Texas A & M University; Miss Barbara Lawrence, Museum of Comparative Zoology, Harvard University. Messrs. Jerry R. Choate and H. H. Genoways, two colleagues in zoology at The University of Kansas, have assisted me in many ways, for which I am grateful. Linda Anne Phillips, my wife, prepared many of the figures and tables used herein. I thank also Setsuko Nakata, Edwin H. Bryan, Robert Bowan, and Ilse Koehler, who, as staff members of the Bishop Museum, were especially helpful to me. Most of the specimens reported herein were collected by Philip Temple and Peter Shanahan. Key to Genera 1. Uropatagium lacking, or, if present, deeply indented in center; tail vertebrae absent, or if present, free 2 1'. Uropatagium present, not indented; tail vertebrae present, free or in uropatagium MICROCHIROPTERA 1 2(1). External tail-vertebrae lacking, or, if present, less than 3 mm long 3 2'. External tail-vertebrae more than 3 mm long 6 3(2). Small or medium-sized (forearm less than 50); tongue long, extensile 4 3'. Large (forearm more than 80); tongue not long and extensile 5 4(3). Uropatagium present; small claw present on second phalanx of second digit; tail short (about 3 mm) =Macroglossus=, p. 812