Résultats des Campagnes MUSORSTOM publishes papers and monographs on the deep-sea fauna of the tropical Indo-Pacific. In addition to the New Caledonian region, which is the focus of the series, volume 12 (which is volume 161 in the parent series Mémoires du Muséum National d'Histoire Naturelle) deals with other islands and island groups in the tropics, from Indonesia and the Philippines to Polynesia. The 12 contributed papers range from observations on benthic ecology to reports on Xenophyophora, Bryozoa and Crustacea. As with earlier volumes, the present one contains numerous new taxonomical and biogeographical data. One new subfamily, four new genera and 98 new species are described. Novel discoveries include a baffling radiation of 56 new species of galatheids and the occurrence of ditaxiporine bryozoans, a group which first appeared in the Palaeocene and is now represented by only two living species, bath found in deep water south of New Caledonia. Five colour plates provide in situ illustrations of the bottom fauna viewed by submersible, dawn to depths of 2100 m. 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).