A scale-worm with a body of uniform width. Dorsal and ventral surfaces smooth.
Prostomium bilobed, with a peak on each lobe, a median antenna, a pair of small lateral antennae ventrally inserted and a pair of palps. Two pairs of eyes, the anterior pair on the anterior margin near the peaks, the posterior pair in front of the rear margin. First segment bearing 1-2 chaetae and a pair of dorsal and ventral tentacular cirri. Scales overlap completely, covering the body. The first pair of scales are round, the margins with papillae forming a continuous fringe and the surfaces with small tubercles. The rest vary from oval to kidney-shaped, the margins with long papillae on the outer edge and the surfaces with small floret tubercles. Notopodia are small mounds with a ventral acicular ligule and numerous chaetae. Notopodial chaetae spinose with blunt tips. Neuropodia well developed with an anterior acicular ligule and numerous chaetae. Neuropodial chaetae of 3 kinds: 1) upper group of even thickness, spinose with finely pointed bidentate tips; 2) median group with a swollen terminal third, spinose with bidentate tips; 3) lower group spinose with unidentate tips (H. antilopes-detail).
Up to 25 mm for 36 chaetigers.
Sublittoral, 27- 1050 m on muddy or fine sand.
Eastern Atlantic, from Norway to the Mediterranean and from South Africa. Adriatic, English Channel, Skagerrak and Big Belt.