Prostomium, pharynx A barrel-shaped palps (orange dashed outline) and palpophore surface with a single transverse groove (open arrow) Namalycastis abiuma LNG M16Q3 B subconical palps (orange dashed outline) and palpophore surface with several oblique grooves (filled arrows) Neanthes glandicincta MD165 anterior C caecal glands (filled arrows) in ventral dissection of Perinereis vallata NMV F108784 D spherical palpostyles (filled arrow) and prostomium with longitudinal groove (open arrow) Namalycastis abiuma E acutely conical palpostyles (filled arrow) and indented prostomium (open arrow) Gymnonereis minyami F prostomium anterior margin entire Nereis sp. G prostomium anterior margin indented (open arrow) Ceratonereis sp. H dentate jaws (filled arrow) Platynereis bicanaliculata NTM W17252 I smooth/crenulate jaws (white arrow) Leonnates crinitus NTM W3330 J everted pharynx a truncate cone with greatest width at margin of tentacular belt (= “frustrum-shaped”) Alitta sp. NMV F94547 K everted pharynx cylindrical Simplisetia aequisetis NMV F94248 L ventral peristomial flap (filled arrows) and palpostyles subconical to oval-shaped (open arrow) Cheilonereis peristomialis M ventrum of anterior chaetigers with rows of tubercles extending to the base of each neuropodium (filled arrows) Australonereis ehlersi N ventrum of anterior chaetigers smooth Neanthes sp. NMV F182608 O dorsal view pharynx with numbering following Kinberg Perinereis vallata P ventral view pharynx with numbering following Kinberg Perinereis vallata. Sources: A, B, F, H, I, M C. Glasby photographs C, J, K, N R. Wilson photographs D modified after C. Glasby (1999) E modified after Hutchings and Reid (1990) G Leon Altoff photograph L, O, P R. Wilson drawings. Not to scale; body widths of these example specimens are in the range 2–5 mm wide excluding parapodia.