The present volume is published 25 years after the inception of the IRD-MNHN expeditions to explore the deep-water benthos of the South Pacific. What used to be « Musorstom expeditions » focused on New Caledonia later became the « Tropical Deep-Sea Beuthos » programme, expanding to the Solomons, Vanuatu, Fiji, Tonga, and French Polynesia, as well as to Southeast Asian seas. They generated moments of scientific discovery of a magnitude and intensity that can only be compared to the famous « historical expeditions », the Challenger, the Albatross or the Siboga.
The series Tropical Deep-Sea Benthos, named after the programme, represents only the tip of an iceberg of literally hundreds of resulting scientific articles. The present volume specifically contains results on molluscs, covering Polyplacophora (1 paper), bivalves (2), scaphopods (1) and gastropods (5), describing altogether no less than 159 new species and 13 new genera. Several authors are non-professionals, and their place in this volume confirms the role of amateur experts in modern alpha-taxonomy.
New Caledonia emerges from this volume as a confirmed centre of species richness for certain taxa (e.g., scaphopods, marginellids, coralliophilines) whereas the Philippines remain at the top of the list for others (e.g., lucinids, cassids), undoubtedly reflecting differences in both biogeographical patterns and sampling intensity.