Polychaetes from the Mariana Islands of Guam and Saipan have been characterized in previous studies but a thorough taxonomic study of the cirratulids has only been possible recently. Here we report on two new records, Caulleriella pacifica and Chaetozone flagellifera, and a new species, Monticellina lueldredgei, sp. nov. The species C. pacifica is newly recorded for the western Pacific while C. flagellifera is reported for the first time since its original description. The new species M. lueldredgei is unique in the genus with respect to the ultrastructure and segmental origin of the modified capillaries as well as for the distinctive methyl green staining pattern.
