Gymnonereidinae new subfamily: the Nereididae (Polychaeta) with bifid parapodial neurocirri

Among the Nereididae without (hardened chitinous?) paragnaths, the genera with bifid parapodial neurocirri have in common also a pronounced inequality between the anterior and medio-posterior body regions in the number of setae per parapodium; this leads to a peculiar habitus of most of these forms. A new subfamily, GYMNONEREIDINAE is proposed for the previously recognized genera Ceratocephale Malmgren, Gymnonereis Horst, Tambalagamia Pillai and Micronereides Day. Two new species, Ceratocephale hartmanae and C. oculata, are described, and additions to the descriptions of 8 of the previously known 9 other members of the family made, primarily based on a study of type material Ceratocephale loveni, C. pacifica, Gymnonereis crosslandi (Ceratocephal crosslandi Hartman 1952), G. fauveli, Micronereides capensis, Tambalagamia fauveli. Generic diagnoses are amended.