Body with fewer than 50 segments. Prostomium with cephalic peaks; median antenna in anterior notch, style smooth; lateral antennae inserted ventrally, styles smooth; anterior pair of eyes dorsolateral on widest part of prostomium, posterior pair dorsal near hind margin of prostomium; palps papillate, tapering.
Tentaculophores lateral to prostomium, each with a single notochaeta and a dorsal and ventral tentacular cirrus. Second segment with first pair of elytra, biramous parapodia, and long buccal cirri.
Fifteen pairs of elytra, covering dorsum (in large specimens dorsum in mid-body region uncovered), on segments 2, 4, 5, 7, then on every second segment to 23, 26, 29, 32; last segments cirrigerous; elytral margin smooth; elytral surface with conical mircotubercles with blunt to pointed tip; thorn-shaped macrotubercles scattered in posterior half of elytron, mainly near outer lateral and posterior margin. Cirrigerous segments with globular dorsal tubercles; dorsal cirri with cylindrical cirrophore and smooth style, slightly inflated subdistally, then abruptly tapering. Ventral cirri with smooth, tapering style.
Parapodia biramous; notopodia of about same size as neuropodia with elongate acicular lobe; neuropodia with elongate prechaetal acicular lobe with digitiform supra-acicular process; neuropodial postchaetal lobe shorter than prechaetal lobe, rounded; tips of noto- and neuroacicula penetrating epidermis. Notochaetae of two kinds independent of size of individual: short, stout notochaetae with rows of spines and more or less pointed tip, and long, stout notochaetae projecting dorsally to meet mid-dorsally with blunt tip and shaft usually smooth (in smaller specimens few rows of spines present distally). Neurochaetae falcate with unidentate tip; one or two neurochaetae with subdistal slit suggesting presence of secondary tooth (but never distinctly bidentate as in Harmothoe).
Size of large specimen, for example: length 50 mm, width 15 mm for 42 segments.