The nereidid polychaete genus Namalycastis Hartman, 1959 has been recorded almost exclusively in non-marine environments. This genus includes species having four pairs of tentacular cirri, and its species mainly differ by the relative size of dorsal cirri in posterior chaetigers. Namalycastis occulta n. sp. is described based upon non-mature and mature specimens collected in the intertidal from...

A new species of Polydora is described from the Catalan coast of the north western Mediterranean Sea. The species has exclusively been found in association with specimens at the three growth stages of the excavating sponge Cliona viridis, and is closely related to Polydora armata. It mainly differs from its closest relatives by: (l) the rounded entire anterior margin of the prostomium; (2) the ...

A large collection of scalibregmatid polychaetes from the east Antarctic Peninsula in May 2000 has yielded specimens of three new species of Scalibregma, Pseudoscalibregma, and Oligobregma. The new species of Scalibregma is represented by more than 400 specimens that include post-larval and juvenile forms which, for the first time, provide data on the sequence of development of key characters o...