Noves localitzacions d'Opistobranquis als Països Catalans

New data are presented on the geographical distribution of Opisthobranch molluscs in the Catalan Countries (Catalonia, Valencia and the Balearic Islands). Despite recent studies of this group along the Catalan coast, there is still much to be known about them, especially the Pyramidellids. Most of the species mentioned here have been found in tanatocoenoses.