Terebellides Sars 1835

Genus Terebellides Sars, 1835 Type species: Terebellides stroemii Sars, 1835 Diagnosis (after Lavesque et al. 2024). Transverse prostomium attached to the dorsal surface of the upper lip; basal part as a thick crest, eyespots rarely present; distal part extending along the upper lip until near the anterior border of the lip. Buccal tentacles of two types, uniformly cylindrical and expanded at the tips, spatulate. Peristomium forming lips; lips expanded, circular upper lip, distal margin convoluted; expanded lower lip, scoop-shaped, with a large marginal lobe. Segment 1 short, conspicuous all around or only visible ventrally; following anterior segments with lobes as low ventral collars, frequently protruding laterally for short extension on segments 2–4, at least. Branchiae as single, stalked, four to five lobed structure, inserted mid-dorsally on segments 2–3 or 2–4, lobes in two pairs, each with multiple lamellae with ciliary tracts and rows of ciliated papillae; a fifth anterior lobe often present. Notopodia beginning on segments 3 or 4, usually 3, extending for 17–18 segments, until segment 20; narrowly winged notochaetae in both rows throughout. Neuropodia beginning from segments 7 or 8, usually 8; sessile thoracic neuropodia, uncini emerging directly from the body wall; first pair of neuropodia or first two pairs, when beginning from segment 7, with subdistally bent, distally tapered spines, from segment 9 thoracic neurochaetae as avicular uncini, hood below the main fang absent, crest with relatively few transverse rows of secondary teeth; abdominal neuropodia as foliaceous pinnules, bearing avicular uncini, with rows of secondary teeth on top and lateral to the main fang. Nephridial papillae only on segment 3, genital papillae, if present, normally on segments 6–7, at bases of notopodia, posterior and dorsal. Pygidium smooth to slightly crenulate.