RIASSUNTO
Deep waters of the South Pacific off northern Chile remain poorly studied, particularly in regard to invertebrate faunas. Some recent works include new records on deep-water species, mostly from the bycatch of benthic fisheries concentrated along the continental margin of the country. Among these, a few specimens of an unidentified bathylasmatine balanomorph were collected off Caldera, northern Chile, and they are described here as Bathylasma chilense sp. nov. While this is the second report of a bathylasmatid in the Eastern Pacific Ocean, the first being Tetrachaelasma southwardi Newman & Ross, 1971, it is not only the first but the deepest known (1800–2000 m) species of Bathylasma. Its discovery increases the number of described Bathylasma species to eight, four of which are extant. This is the third deep-water balanomorph cirriped recorded for the region where it may represent an isolate from a West Wind Drift fauna, an immigrant from the western Pacific, or a relict of a once cosmopolitan Paleocene-Eocene fauna now having an amphitropical component.