The Journal of the Geological Society of Japan

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As the writer discussed the mammalian faunas of our country and classified them into seven faunas including four subfaunas on a former occasion, he went a step further in this paper and looked into eleven species which are important elements in some of these faunas., The conclusion at which he arrived are summarized below., a) Hemimastodon ancectens with which Trilophodon sendaicus, T., palaeindicus, Bunolophodon yokotii and ? Pentalophodon sp., are identifiable may be an indicator of the Hiramakian stage, or of the Burdigalian stage in Japan., Incidentally it is noted that Hemimastodon is a synonym of Bunolophodon, as already claimed by J., MAKIYAMA., b) Mastodon aff., latidens from Hanareyama, Ibaraki prefecture coincides with Stegodon elephantoides (CLIFT) in every detail and furthermore, agreeing with J., MAKIYAMA, the writer thinks it reasonable to refer Stegodon orientalis from Kusunokibara, Mie prefecture to S., elephantoides., c) Of Stegodon sinensis OWEN, S., orientalis OWEN, Parastegodon aurorae (MATSUMOTO), P., akashiensis TAKAI and Parelephas proximus (MATSUMOTO), all important members of the older Pleistocene fauna, it is noted (1) that the first species is different from Stegodon etephantoides in several respects mention of which is given in the Japanese text, and (2) that the answer to the question as to whether the first and second species are synonymous with each other or not is in the offing., However, in case the former alternative is correct, the name, sinensis must remain valid because the description of sinensis stands prior to that of the other in the same volume., d) The longitudinal section of the valley is V-shaped in Stegodon orientalis shodoensis whereas it is U-shaped in Parastegodon akashiensis., e) The prime distinctions between Stegodon and Parastegodon lie in the longitudinal section of the valley and the amount of the cementing matter ; namely, the section is U-shaped in the latter and V-shaped in the former ; the deposition of cement is more plentiful in the former than in the latter., f) Parastegodon kwantoensis, P., sugiyamai and certain specimens of P., akashiensis may safely be referred to P., aurorae., g) Parastegodon infrequens and ? Archidiskodon planifrons are synonyms of Parastegodon akashiensis., h) While the type specimen of Parelephas protomammonteus typicus is identical with Palaeoloxodon namadicus naumanni, certain specimens referred to Paralephas protomammonteus typicus, P., protomammonteus matsumontoi and P., proximus uehataensis belong to Parelephas proximus (MATSUMOTO)., i) Palaeoloxodon namadicus naumanni (MAKIYAMA), Palaeoloxodon namadicus aomoriensis TOKUNAGA and TAKAI and Elephas mammonteus CUVIER are important elements of the latest pleistocene fauna where the first comprises the forms described under the names of Elephasnamadicus namadi, Loxodonta (Palaeoloxodon) tokunagai, Parelephas protomammonteus typicus, Loxodonta (Palaeoloxodon) namadica yabei, Elephas (Palaeoloxoden) namadicus setoensis and Palaeoloxodon yokohamanus., Elephas mammonteus, Mammonteus primigenius and Parelephas armeniacus belong to an identical species, and among the three names the first is the valid one as pointed out by J., MAKIYAMA., j) Desmostylus japonicus TOKUNAGA and IWASAKI is a characteristic faunal element of the Togarian stage i., e., of the Vidobonian stage in Japan and Desmostylus mirabilis, D., minor, D., sp., and Desmostylella typica fall within the bound of variability of D., japonicus.,

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