This revised catalogue includes all the Mesozoic Bivalvia hitherto described from Japan and its adjacent areas (Saghalin, Kurile, Korea and Formosa). The following format and abbreviations are adopted.

Taxonomic names. —Revised taxonomic names are written in bold-faced letters. A question mark placed after a generic name indicates that the generic reference is doubtful. "cf." after a name of indeterminable species indicates the occurrence of comparable specimen(s) with the next coming taxon. "aff." means the occurrence of not identical but morphologically similar specimens(s). Both of these expressions are used primarily for indicating the relation to foreign species. Comparable specimen(s) with domestic taxa are listed in synonymies with the prefix "compare".

Synonymies. —An attempt has been made to provide complete synonymies which appeared in descriptive works. Omitted are the synonyms on the materials from other countries and those appeared in faunal lists without description, citations in comparative studies, picture books with no original illustration, guide books on local faunas and various unscientific accounts. For brevity, references are designated only by author name and year in the text. The full reference including the title of periodical and number of volume (series or section in brackets and number or part in parentheses) will be found in the bibliography. The author name of original publication, if it is the same as the author name of the taxon, is not repeated. "sic" indicates the exact spelling of taxonomic name which is incorrect. Typographical errors are corrected with brief annotations.

Type. —Only information about primary type-specimen(s) is indicated. The categories of types, namely, holotype (by original designation or by monotypy), syntype, lectotype or neotype, are distinguished. Information about the valid designation of lectotype (if any) and the depository, register number and locality of type-specimen(s) are also added. Type-specimens of the taxa proposed for foreign materials are not treated here. If only one of the syntype specimens was illustrated in the original description, it is usually designated here as the lectotype; in other cases, however, new designation of lectotype is generally avoided here, because such a procedure should be desirably accompanied by particular investigation on the taxon. The place names of type localities are modernized in accordance with the present administrative division. The information about the categories of type-specimens and depositories given in "Catalogue of type-specimens of fossils in Japan" (Hanzawa, Asano and Takai, 1961 ed.) is not always correct as to the Mesozoic Bivalvia; hence some disagreement will be found.

Depository. —The following abbreviations are used for the indication of the institutions where the type-specimens are actually (or said to be) preserved.

GMH:

Department of Geology and Mineralogy, Faculty of Science, Hokkaido University, Sapporo

IGPS:

Institute of Geology and Palaeontology, Faculty of Science, Tohoku University, Sendai

GIUM:

Department of Earth Sciences, Faculty of Science, Ibaraki University, Mito

UMUT:

University Museum, the University of Tokyo, Tokyo (specimens transferred from Geological Institute, Faculty of Science, the University of Tokyo)

CU:

Geological Institute, Faculty of Science, Chiba University, Chiba

GSJ:

Geological Survey of Japan, Kawasaki

GYU:

Department of Geosciences, Faculty of Education, Yokohama National University, Yokohama

UK:

Geological and Mineralogical Institute, Faculty of Science, Kyoto University (the University of Kyoto), Kyoto

OCU:

Department of Geosciences, Faculty of Science, Osaka City University, Osaka

OMN:

Osaka Museum of Natural History, Osaka

IGSH:

Institute of Geology and Mineralogy, Faculty of Science, Hiroshima University, Hiroshima

GF:

Department of Geology, Fukuoka University of Education, Munakata

GK:

Department of Geology, Faculty of Science, Kyushu University, Fukuoka

KU:

Department of Geology, Faculty of Science, Kumamoto University, Kumamoto

KE:

Department of Geosciences, Faculty of Education, Kumamoto University, Kumamoto

Age. —Vertical range of each taxon in Japan and its adjacent regions is indicated primarily by means of international (Tethyan) stage names. Because fossil bivalves often are not accompanied by ammonites and any other index fossils, the age of fossil beds is not necessarily determinable with reliable evidences. The range of some taxa, especially non-marine and brackish-water species, is inevitably shown more roughly.

Distribution. —Stratigraphic and geographic distribution of each taxon is indicated by the names of strata and areas. Distribution in other countries is only briefly noted. The data were derived mainly from previous descriptive studies cited in the above synonymies but partly supplemented by other undescribed materials here examined. Occurrence of comparable specimens is not considered. The geographic position of Mesozoic areas in question is indicated in the annexed index maps (Figs. 1-3).

Fig. 1. Map showing the distribution of Triassic formations bearing fossil bivalves in Japan 1. Motoyoshi area in Miyagi Pref. (Low.-Mid. Triassic Inai group) 2. Shizukawa area in Miyagi Pref. (Low.-Mid. Triassic Inai group, Up. Triassic Saragai group) 3. Rifu area in Miyagi Pref. (Mid. Triasaic Rifu group) 4. Ome area in Tokyo Pref. (Up. Triassic Kochigatani group) 5. Itsukaichi area in Tokyo Pref. (Triassic Arai formation, Up. Triassic Kochigatani group) 6. Sanchu area in Gumma Pref. (Low. Triassic Shionosawa limestone) 7. Ibuki area in Gifu Pref. (Up. Triassic Myogatani formation) 8. Western hills of Kyoto, Kyoto Pref. (partly Up. Triassic Tano formation) 9. Maizuru zone in Fukui, Kyoto and Hyogo Prefs. (Low.-Mid. Triassic Yakuno group, Triassic Shidaka group, Triassic Miharaiyama group, Up. Triassic Nabae group. Up. Triassic Heki formation) 10. Aita area in Okayama Pref. (Low.-Mid. Triassic Fukumoto group) 11. Nariwa area in Okayama Pref. (Up. Triassic Kyowa formation, Up. Triassic Nariwa group) 12. Miwa area in Yamaguchi Pref. (partly Up. Triassic Kuga group) 13. Asa area in Yamaguchi Pref. (Up. Triassic Mine group, Up. Triassic Kamosho formation) 14. Mine area in Yamaguchi Pref. (Mid. Triassic Atsu group, Up. Triassic Mine group) 15. Sakuradani area in Tokushima Pref. (Mid. Triassic Zohoin group, Up. Triassic Kochigatani group) 16. Nangoku area in Kochi Pref. (Low. Triassic Kurotaki formation) 17. Ino area in Kochi Pref. (Mid. Triassic Zohoin group, Up. Triassic Kochigatani group) 18. Sakawa area in Kochi Pref. (Mid. Triassic Zohoin group, Up. Triassic Kochigatani group) 19. Uonashi area in Ehime Pref. (Low. Triassic Taho formation, unnamed Mid. Triassic formation) 20. Takachiho area in Miyazaki Pref. (Low. Triassic Kamura formation) 21. Miyamadani area in Kumamoto Pref. (Up. Triassic Kochigatani group) 22. Sakamoto area in Kumamoto Pref. (Up. Triassic Kochigatani group) 23. Tanoura area in Kumamoto Pref. (Up. Triassic Kochigatani group) 24. Yamae area in Kumamoto Pref. (partly Mid ? Triassic Konose group) 25. Motobu area in Okinawa Pref. (partly Up. Triassic Nakijin formation)

Fig. 2. Map showing the distribution of Jurassic formations bearing fossil bivalves in Japan 1. Karakuwa, Kesennuma and Oshima areas in Miyagi Pref. (Mid. Jurassic Karakuwa group, Up. Jurassic-Lowest Cretaceous Shishiori group) 2. Shizukawa area in Miyagi Pref. (Low. Jurassic Shizukawa group, Mid.-Up. Jurassic Hashiura group) 3. Hasbiura area in Miyagi Pref. (Low. Jurassic Shizukawa group, Mid.-Up. Jurassic Hashiura group) 4. Mizunuma area in Miyagi Pref. (Low. Jurassic Shizukawa group, Mid.-Up. Jurassic Hashiura group) 5. Ojika area in Miyagi Pref. (Mid. Jurassic-Lowest Cretaceous Ojika group) 6. Soma area in Fukushima Pref. (Mid. Jurassic-Lowest Cretaceous Soma group) 7. Katashina area in Gumma Pref. (Low. Jurassic Iwamuro formation) 8. Minamimaki area in Nagano Pref. (Up. Jurassic Torinosu group) 9. Otari area in Nagano Pref. (Low. Jurassic Kuruma group) 10. Kotaki area in Niigata Pref. (Low. Jurassic Kuruma group) 11. Omi area in Niigata Pref. (Low. Jurassic Kuruma group) 12. Asahi area in Toyama Pref. (Low. Jurassic Kuruma group) 13. Arimine area in Toyama Pref. (Mid. Jurassic-Cretaceous Tetori group) 14. Yatsuo area in Toyama Pref. (Mid. Jurassic-Cretaceous Tetori group) 15. Furukawa area in Gifu Pref, (Mid. Jurassic-Cretaceous Tetori group) 16. Makito area in Gifu Pref. (Mid. Jurassic-Cretaceous Tetor; group) 17. Izumi (Kuzuryu) area in Fukui Pref. (Mid. Jurassic-Cretaceous Tetori group) 18. Oosa area in Okayama Pref. (Low. Jurassic Yamaoku formation) 19. Toyoda area in Yamaguchi Pref. (Low.-Mid. Jurassic Toyora group) 20. Sakuradani area in Tokushima Pref. (Up. Jurassic Torinosu group) 21. Sakawa area in Kochi Pref. (Up. Jurassic Torinosu group) 22. Sakamoto area in Kumamoto Pref. (Up. Jurassic Torinosu group) 23. Tanoura area in Kumamoto Pref. (Up. Jurassic Torinosu group)

Fig. 3. Map showing the distribution of Cretaceous formations bearing fossil bivalves in Japan 1. Nakagawa and Abeshinai areas in Teshio Prov., Hokkaido (Up. Cretaceous Middle Yezo group, Up. Cretaceous Upper Yezo group) 2. Haboro area in Teshio Prov., Hokkaido (Up. Cretaceous Upper Yezo group) 3. Esashi area in Kitami Prov., Hokkaido (Low. Cretaceous Horombetsu formation) 4. Sorachi area in Ishikari Prov., Hokkaido (Low. Cretaceous Lower Yezo group) 5. Ikushumbetsu area in Ishikari Prov., Hokkaido (Low.-Up. Cretaceous Middle Yezo group, Up. Cretaceous Upper Yezo group) 6. Yubari, Oyubari and Manji areas in Ishikari Prov., Hokkaido (Low.-Up. Cretaceous Middle Yezo. group, Up. Cretaceous Upper Yezo group) 7. Akkeshi area in Kushiro Prov., Hokkaido (Up. Cretaceous Neumuro group) 8. Urakawa area in Hidaka Prov., Hokkaido (Up. Cretaceous Upper Yezo group) 9. Hobetsu and Hetonai areas in Iburi Prov. and Hiratori area in Hidaka area (Up. Cretaceous Upper Yezo group, Up. Cretaceous Hakobuchi group) 10. Kuji area in Iwate Pref. (Up. Cretaceous Kuji group) 11. Tanohata area in Iwate Pref. (Low. Cretaceous Miyako group) 12. Omoto area in Iwate Pref. (Low. Cretaceous Miyako group) 13. Miyako area in Iwate Pref. (Low. Cretaceous Miyako group) 14. Omine area in Iwate Pref. (Low. Cretaceous Kamihei group) 15. Ofunato area in Iwate Pref. (Low. Cretaceous Ofunato group) 16. Oshima area in Miyagi Pref. (Low. Cretaceous Oahima formation) 17. Hashiura area in Miyagi Pref. (Low. Cretaceous Jusanhama group) 18. Futaba area in Fukushima Pref. (Up. Cretaceous Putaba group) 19. Nakaminato area in Ibaraki Pref. (Up. Cretaceous Nakaminato group) 20. Choshi area in Chiba Pref. (Low. Cret. Choshi formation) 21. Sanchu area in Gumma and Naganb Prefs. (Low. Cretaceous Ishido and Sebayashi formations) 22. Nakagomi area in Nagano Pref. (Up. Cretaceous unnamed formation) 23. Toyama area in Nagano Pref. (Low. Cret. unnamed formation) 24. Takato area in Nagano Pref. (Low. Cretaceous Todai formation) 25. Misakubo area in Shizuoka Pref. (Up. Cretaceous Misakubo formation) 26. Shiramine area in Ishikawa Pref. (Jurassic-Cretaceous Tetori group) 27. Kitadani area in Fukui Pref. (Jurassic-Cretaceous Tetori group) 28. Shima area in Mie Pref. (Low. Cretaceous Matsuo group) 29. Yuasa area in Wakayama Pref. (Low. Cretaceous Yuasa, Arita, Izeki and Nishihiro formations 30. Kanaya area in Wakayama Pref. (Up. Cretaceous Kanaya and Toyajo formations) 31. Yura area in Wakayama Pref. (Up. Cretaceous Terazoma formation) 32. Izumi mountains in Osaka and Wakayama Prefs. (Up. Cretaceous Izumi group) 33. Awaji island in Hyogo Pref. (Up. Cretaceous Izumi group) 34. Shimonoseki area in Yamaguchi Pref. (Low. Cretaceous Yoshimo formation) 35. Takibe area in Yamaguchi Pref. (Low. Cretaceous Kwanmon group) 36. Hiketa area in Kagawa Pref. (Up. Cretaceous Izumi group) 37. Katsuuragawa area in Tokushima Pref. (Low. Cretaceous Tatsukawa, Hanoura and Hoji formations, Up. Cretaceous Tatsue formation) 38. Monobegawa area in Kochi Pref. (Low Cretaceous Hagino formation or Lower Monobegawa group) 39. Nangoku area in Kochi Pref. (Low. Cretaceous Lower Monobegawa group) 40. Sakawa and Ochi areas in Kochi Pref. (Low. Cretaceous Lower Monobegawa group,/Upper Cretaceous Miyanohara formation) 41. Susaki area in Kochi Pref. (Low. Cretaceous Doganaro formation) 42. Onsen area in Ehime Pref. (Up. Cretaceous Izumi group) 43. Kurosegawa area in Ehime Pref. (Low. Cretaceous Kikunotani formation) 44. Uwajima area in Ehime Pref. (Up. Cretaceous Uwajima group) 45. Johen area in Ehime Pref. (Up. Cretaceous Ippommatzu formation) 46. Kurate area in Fukuoka Pref. (Low. Cretaceous Kwanmon group) 47. Yahata area in Fukuoka Pref. (Low.-Up. Cretaceous Kwanmon group) 48. Nozu area in Oita Pref. (Low. Cretaceous Haidateyama formation, Up. Cretaceous Tano formation) 49. Onogawa area in Oita Pref. (Up. Cretaceous Onogawa group) 50. Minine, Mashiki and Matsubase areas in Kumamoto Pref. (Up. Cretaceous Mifune group) 51. Tomochi area in Kumamoto Pref. (Low. Cretaceous Tomochi formation) 52. Yatsushiro area in Kumamoto Pref. (Low. Cretaceous Yatsushiro formation, Up. Cretaceous Miyaji formation 53. Sakamoto and Toyo areas in Kumamoto Pref. (Low. Cretaceous Kawaguchi, Hachiryuzan, Hinagu and Yatsushiro formations) 54. Amakusa islands and Uto peninsula in Kumamoto Pref. (Up. Cretaceous Himenoura group) 54a: Amakusa-kamishimai 54b: Amakusa-shimoshima 55. Gosyonoura (= Goshonoura) island in Kumamoto Pref. (Low.-Up. Cretaceous Gosyonoura group, Up. Cretaceous Himeaoura group) 56. Shishijima and Nagashima islands, Kagoshima Pref. (Low.-Up. Cretaceous Gosyonoura group, Up. Cretaceous Himenoura group) 57. Shimo-koshiki island, Kagoshima Pref. (Up. Cretaceous Himenoura group)