Opisthodonta Langerhans, 1879

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 : 300

Genus Opisthodonta Langerhans, 1879

Opisthodonta Langerhans, 1879: 547 .

Type species. Opisthodonta morena Langerhans, 1879 .

Diagnosis. Body long, with numerous segments, stout, dorsally convex, of macrofaunal size (> 10 mm in length). Prostomium provided with 2 pairs of eyes, and sometimes 2 anterior eyespots. Three antennae. Median antenna inserted on middle of prostomium or slightly in front of anterior eyes. Palps apparently free from each other, basally fused. Peristomium small, partially covered by prostomium and first chaetiger, with 2 pairs of tentacular cirri. Nuchal organs as 2 ciliated grooves between prostomium and peristomium. Dorsal cirri on all chaetigers, cylindrical, long to extremely long, smooth or slightly rugose. Parapodia elongate; ventral cirri of anterior parapodia, ovate, foliaceous almost completely fused with parapodial lobe, provided with hyaline inclusions, perhaps glands. Subsequent ventral cirri conical to digitiform, neither foliaceous nor fused to parapodial lobes, inserted at base of parapodia. Chaetal bundles formed of numerous compound chaetae, including falcigers provided with long, thick proximal tooth and short distal tooth and sometimes a few chaetae with long, slender, spiniger-like blades. Dorsal simple chaetae apparently lacking. Aciculae with buttonshaped tips with crown of spines, or tricuspidate. Pharynx and proventricle similar in length. Pharynx with crown of soft papillae on anterior rim and single mid-dorsal tooth, inserted on anterior third or middle of pharynx. Reproduction by epigamy ( Garwood, 1991).