A new species of Odontosyllis Claparède, 1863 (Annelida, Syllidae) with re-descriptions of O. liniata Hartmann-Schröder, 1962 and O. gymnocephala Hartmann-Schröder, 1965 Author Verdes, Aida Author Pleijel, Fredrik Author Aguado, Teresa text Zootaxa 2011 3095 27 38 journal article 46016 10.5281/zenodo.201246 723e4f05-a55d-4c97-bf3b-e3c2c256dd05 1175-5326 201246 Genus Odontosyllis Claparède, 1863 Odontosyllis Claparède, 1863: 47 ? Eurymedusa Kinberg, 1865 : 249 Parautolytus Ehlers, 1900 : 213 Alluaudella Gravier, 1905 : 372 ? Atelesyllis Pruvot, 1930 : 39 Pharyngeovalvata Day, 1951 : 26 Odontoautolytus Hartmann-Schröder, 1979 : 112 ? Synpalposyllis Hartmann-Schröder, 1983 : 132 Umbellisyllis Sars, 1869 : 254 Type species. Odontosyllis fulgurans ( Audouin & Milne-Edwards, 1833 ) Diagnosis (modified from San Martín & Hutchings 2006 ). Adult size variable, 5–10 mm long, with numerous segments, dorsally convex and flattened ventrally. Prostomium with four eyes and, occasionally, a pair of anterior eyespots. Three antennae. Palps broad, separated for almost all their length, basally fused. First segment usually reduced dorsally; two pairs of tentacular cirri. Occipital flap present, usually well developed, covering first segment dorsally and posterior part of prostomium. Nuchal organs as two ciliated grooves between prostomium and first segment, sometimes extending to lateral areas of prostomium. Dorsal cirri elongated, smooth, distally tapered, but sometimes short or indistinctly articulated. Parapodia usually with pre- and postchaetal lobes. Ventral cirri digitiform to pillow-shaped. Compound chaetae heterogomph, usually with distally spinose shafts. Dorsal and sometimes ventral simple chaetae present on some parapodia. Pharynx short, distinctly shorter than proventricle, provided with few teeth directed backwards and two lateral plates; pharynx when not everted situated posterior to first chaetiger. Proventricle usually long, wide and massive. Pygidium with two anal cirri.Reproduction by epigamy; epigamic specimens sometimes strongly modified and bioluminescent ( San Martín & Hutchings, 2006 ). Remarks . Unlike San Martín & Hutchings (2006) , we follow Rouse & Pleijel (2001) and Pleijel (2001) for interpretation of Odontosyllis anterior appendages. These authors suggested that the two first pairs of cirri appendages in Syllidae may be named in accordance with other taxa in Phyllodocida . The interpretation of these appendages becomes crucial for homology statements with other families and thereby for our understanding of the position of the group. San Martín & Hutchings (2006) synonymised several genera with Odontosyllis that previously were poorly known with regard to the structure of the pharynx. They also suggested that Eurymedusa Kinberg, 1865 , Atelesyllis Pruvot, 1930 , and Synpalposyllis Hartmann-Schröder, 1983 , may be synonymous with Odontosyllis , although they could not obtain relevant information from the types since they either had been lost, or were in too poor condition. Alluaudella Gravier, 1905 was considered synonymous with Odontosyllis by Aguado & San Martín (2008).