Bergendal, 1893
Description:
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. Lang's vesicle 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.
Habitat:
On mud, muddy sand, shells, gravel and among algae between 7 and 300 m.
Distribution:
Shetland Islands, Denmark, Norway and Sweden.