Leucia Malmgren, 1867

Type species. Polynoe nivea M. Sars, 1863

Diagnosis. Body dorsoventrally flattened, short, with up to 50 segments; dorsum more or less covered by elytra or short posterior region uncovered. Sixteen pairs of elytra on segments 2, 4, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 26, 29, 32, and 35. Prostomium with distinct cephalic peaks and three antennae with lateral antennae inserted ventrally to median antenna. Anterior pair of eyes dorsolateral at widest part of prostomium, posterior pair dorsal near hind margin. Parapodia with elongate acicular lobes with both acicula penetrating epidermis; neuropodia with a supra-acicular process. Notochaetae stout with distinct rows of spines and blunt to pointed tip. Neurochaetae more numerous and more slender, with distinct rows of spines distally and bi- and unidentate tips.