A scale-worm with an elliptical body. Dorsal surface smooth; ventral surface densely papillate.
Prostomium round with a median antenna on a large base, a pair of non-pigmented eye stalks and a papillate facial tubercle. A ridge extends from the median antenna posteriorly and laterally along the posterior margin.
First segment well developed, directed forward with numerous capillary chaetae and a pair of dorsal and ventral tentacular cirri.
Scales overlap, covering the body. They occur on segments 2, 5 and 7 then alternately to the 25th and then segments 30 and 31. The first pair of scales are round, attached in the middle, the rest round to rectangular. attached by a stalk and also along the dorsal surface of the notopodium, partly enveloping the notopodial mound. All scales with smooth margins and surfaces.
Notopodia with scales have an acicular leaf-shaped ligule posterior to the chaetae, notopodia without scales have irregular shaped mounds with the pointed acicular ligule anterior to the dorsal cirri.
Notopodial chaetae of 3 kinds: 1) fine capillaries on segments without scales, forming a thin layer of pseudo-felt with mucus and attached sand grains; 2) stout capillaries on segments without scales; 3) harpoon chaetae on segments with scales.
Neuropodia narrow and longer than notopodia, with few chaetae. Neuropodial chaetae of 2 kinds: 1) stout, curved, unidentates with a prominent lower tooth and a row of filamentous hairs on the recurved surface; 2) laterally spinose chaetae (L. filicornis-detail).
Up to 40 mm for 35 chaetigers.
Body and scales pale grey/white.
Sublittoral to 3500 m, on sponge or oyster grounds, stones, coral or muddy sand.
North Atlantic up to West Indies, northern North Sea, Skagerrak, Kattegat and Öresund.