Eusyllis Malmgren, 1867

San Martin, G & Hutchings, PA, 2006, Eusyllinae (Polychaeta: Syllidae) from Australia with the Description of a New Genus and Fifteen New Species, Records of the Australian Museum 58, pp. 257-370 : 271

Genus Eusyllis Malmgren, 1867

Eusyllis Malmgren, 1867: 40 .

Eudontosyllis Knox, 1960: 105 .

Type species. Eusyllis blomstrandi Malmgren, 1867

Diagnosis. Body of medium to small size (10 to <5 mm in length), cylindrical. Prostomium with 4 eyes and sometimes 2 anterior eyespots. Three antennae. Palps either entirely free or fused just basally. Nuchal organs as 2 ciliated grooves, ciliation extending sometimes to prostomium and peristomium, as well as other segments. Two pairs of tentacular cirri. Antennae, tentacular and dorsal cirri nonarticulated, sometimes rugose, with pseudoarticulate appearance. Compound chaetae; dorsal and ventral simple chaetae on some parapodia. Pharynx with mid-dorsal tooth, usually large and conspicuous, and incomplete crown of small denticles, anteriorly pointing. Pygidium with 2 anal cirri. Reproduction by epigamy ( Garwood, 1991).

Remarks. Eusyllis is characterized by having an incomplete trepan on the pharynx, with all teeth anteriorly directed, and a mid-dorsal, usually large, tooth. Species of this genus are typically large, even so the denticles of the trepan are small and sometimes difficult to observe, which can lead to misidentifications. Eusyllis brevicirrata Knox & Cameron, 1971 from New Zealand, reported in Australia by Hartmann- Schröder (1985), reproduces by schizogamy (San Martín, pers. observ., on Australian material) so we suggest that this species represents a member of the subfamily Syllinae probably an undescribed genus (San Martín et al., in prep.). Australian material agrees with the original description based on New Zealand material. Eudontosyllis has been recently proposed as a synonymy of Eusyllis by Glasby et al., (in press).