The benthic molluscan species hitherto collected from depth deeper than 5, 000 m in the Japan Trench are reviwed on the basis of literature and published documents. The past collections by research vessels of Russia (ex-USSR) and Japan have been mostly identified to species, but some to only generic level. Additional species have been discovered by recent cruises of reserch vessels such as the R/V Hakuho-Maru, and the submersibles, however, these newer taxonomic results have seldom been made public up to now.
