The body is broadly oval, slightly acuminate anteriorly and rounded posteriorly. It may reach a length of 35 mm. There are no tentacles. The eyes are very small; the paired elongate cerebral eye-clusters have each 20-30 eyes; the paired tentacular eye-clusters, each with fewer eyes, are lying posteriorly and laterally to the cerebral clusters; frontal eyes are strewn over the anterior region; marginal eyes are in several rows anteriorly, decreasing gradually to individual eyes posteriorly.
The colour is variable: whitish or grey, inclined to brown, but sometimes translucent and reddish.
The intestinal trunk is extending a little anteriorly and posteriorly to the pharynx and possesses five pairs of wide lateral branches. The pharynx is moderately folded and centrally placed and comprises less than one-third of the body length.
The male genital pore is situated close behind the pharynx, anteriorly to the female pore, from which it is well separated. From each spermiducal vesicle, a narrow muscular canal runs to unite with the efferent duct of the prostatic organ; penis-papilla short and broad. [t]Lang's vesicle[/t] is elongate; the ductus vaginalis connects the female antrum with the vagina interna. The uterine canals are lateral to the vasa deferentia, not confluent anteriorly.
On mud, muddy sand, shells, gravel and among algae between 7 and 300 m.
Shetland Islands, Denmark, Norway and Sweden.