Unravelling the convoluted nomenclature of Marphysa simplex (Annelida, Eunicidae) with the proposal of a new name and the re-description of species

Marphysa simplex is a name that three species bear within the same genus, but each has different authority and morphological characteristics. This homonymy condition leads to taxonomic confusion finite designation of name-bearing imperative. The current study focuses on two identified as M. Crossland, 1903 Treadwell, 1922 third one, recently considered secondary homonymy, (Langerhans, 1884), also assessed. available type specimens were examined re-described in detail using updated characters original descriptions. 1884) herein judged an indeterminable species. confirmed junior synonym teretiuscula (Schmarda, 1861a) because differences are minimal. Moreover, characteristics similar Group B2 (Sanguinea-group; only compound spinigers), instead Teretiuscula-group (compound spinigers anterior region, subacicular limbate all chaetigers). On other hand, primary homonym Crossland’s replaced by fijiensis nom. nov. with chaetal arrangement A (limbate chaetae only). In conclusion, now unacceptable. hypothesis group redescription given.