Published online by Cambridge University Press: 23 June 2010
A collection of over one hundred specimens of Syllidae (Polychaeta) from the Arctic and sub-Arctic regions has been examined and identified. The specimens were obtained from 26 stations in the Barents Sea, some Norwegian fiords and localities of the northern North Sea. A total of 21 species were identified; three species (Myrianida langerhansi (Gidholm, 1967), Syllides longocirrata Örsted, 1845 and Sphaerosyllis taylori Perkins, 1981) are new reports for the Arctic Ocean; 2 species are new to science, Streptodonta exsulis sp. nov. and Trypanosyllis troll sp. nov. Streptodonta exsulis sp. nov. have 4 thick, distally strongly knobbed aciculae on each anterior parapodia, shifting to a single, slender acicula on posterior parapodia; falcigers and pseudospinigers distally bidentate; and pharyngeal tooth located centrally and relatively close to anterior rim of pharynx. Trypanosyllis troll sp. nov. have 2, occasionally 3 straight aciculae in parapodia protruding out from parapodial lobes; falcigers bidentate; and body surface densely covered by numerous, small papillae. Based on the description of these 2 new species, some modifications are proposed in the diagnoses of the genera Streptodonta San Martín & Hutchings, 2006 and Trypanosyllis Claparède, 1864.