The authors wish to express their appreciation to Dr. J, E. Hazel of the U. S. Geological Survey, Washington, D. C., U. S. A., who read the original manuscript, checked our classification, especially of cytheracean ostracods, and gave us invaluable advice; to Dr. R. M. Forester of the U. S. Geological Survey, Washington, D. C., U. S.A., who also read the original manuscirpt; to Dr. P. J. Jones of the Bureau of Mineral Resources, Geology and Geophisics, Canberra, Australia, who kindly went through our identification of Paleozoic ostracods; to Dr. R. H. Bate of the British Museum (Natural History), London, and Dr. W. Sissingh of the University of Utricht, Netherland, who kindly made their type collections available for study; to Drs. Itaru Hayami, Kiyotaka Chinzei, Tomowo Ozawa, and Toshiyuki Yamaguchi of the University of Tokyo, who gave us prompt help at several stages in the preparation of this manuscript. Photographs taken with the scanning electron microscope were prepared by Dr. Toshiyuki Yamaguchi.

This checklist of the ostracods of Japan and its adjacent seas is prepared in compliance with the request of Professor K. G. McKenzie as a contribution to the "Shallow Marine and Freshwater Ostracoda of Tethys," a research project of the International Paleontological Association. We should also like to express our appreciation to Professor K. G. McKenzie of the Riverina College of Advanced Education, Waga Waga, Australia, for his continued encouragement throughout the course of this study.