The present volume (which is volume 156 in the parent series Mémoires du Muséum National d'Histoire Naturelle) contains 9 contributions on the taxonomy and biogeography of crustaceans, recording a total of 159 species of Mysidacea, Amphipoda, Decapoda. Of these, no less than 72 are new to science, as are 12 genera. These figures confirm the stunning uniqueness of the bathyal fauna in this part of the world. In addition to these zoological papers, this volume contains 3 other contributions: a report on the MUSORSTOM 7 expedition to Wallis and Futuna (South Pacific); station lists of various sampling programs around New Caledonia since May 1989; and a list of 276 bibliographical references to papers reporting results of the exploratory cruises on the bathyal and abyssal fauna of the New Caledonian region. The MUSORSTOM series is a joint program of the Muséum national d’Histoire naturelle and the Institut Français de Recherche Scientifique pour le Développement en Coopération (ORSTOM).