1. Central Institute of Radioisotope Science and Safety Kyushu University Fukuoka 819‐0395 Japan
2. Member of the Anthropological Society of Nippon 3‐56‐1‐302 Shuri‐Yamagawacho Naha, Okinawa 903‐0825 Japan
3. Okinawa Prefectural Archaeological Center Nishihara, Okinawa 903‐0125 Japan
4. The University Museum The University of Tokyo Tokyo 113‐0033 Japan