Frey & Leuckart, 1847
Prostomium with a pair of short antennae without cirrophores, a pair of biarticulate palps and 2 pairs of eyes in a trapezoid arrangement.
Dorsal tentacular cirri longer than ventral ones; second dorsal cirrus reaching chaetiger 3-8, (rarely 15).
Pharynx with a pair of denticulate jaws; oral and maxillary rings with conical paragnaths: group I: 1-6; group II: 2-3 rows; group III: oval; group IV: 4-5 rows; group V: 0-6; group VI: a big one surrounded by 6-7 smaller ones; groups VII-VIII: 2-3 irregular rows (N. succinea-proboscis).
Parapodia of the first two chaetigers uniramous with three lobes. Remaining parapodia all biramous with 4 lobes. In anterior parapodia, the notopodial acicular lobe is bilobed; dorsal cirri as long as or shorter than the parapodial lobes. In posterior chaetigers, the dorsal notopodial lobes are enlarged, with the dorsal cirrus inserted almost terminally. Ventral cirri shorter than lobes (N. succinea-parapodium). Chaetae spinigers and falcigers with a distal ringlet (N. succinea-chaetae).
Up to 190 mm for 160 chaetigers.
Living animal with a dark head and a brownish anterior part; posterior part greenish, yellowish or reddish with white spots, or totally dark.
Dorsal cirri of the 7 chaetigers in males subdistally broadened, distally tapered, anterior 5 ventral cirri similar; dorsal cirri of the modified region with ventral warts. In females dorsal and ventral cirri of the first 5 segments somewhat broadened and in the modified region smooth. In females modified parapodia begin on the 14-19 chaetigers, posterior 25-56 normal again.
North Sea, Channel, Skagerrak, Kattegat.