Body plump, rounded; length up to 12 mm; light translucent brown, with enormous green eyes. Head rounded, short and deep, with eyes occupying the whole of the two sides. The pereion is deep, rounded laterally and dorsally and somewhat compressed laterally; the pleon is slender and the urosome well developed.
Female with the antennae very short, subequal; peduncle of three articles attached to an immoveable basal segment, flagellum scarcely longer than the peduncle. Male with long slender antennae; antenna 2 longer than antenna 1, about two-thirds of the body length. The maxilliped lacks a palp.
Gnathopods 1 and 2 small, simple; carpus with an acute, projecting, disto-ventral lobe; pereiopods 3 to 7 are typically slender and in all pereiopods the coxa is very small. Pleopods are well developed. Uropods 1 to 3 broad, laminar; rami lanceolate, with finely denticulate margins.
In Rhizostoma , Aurelia and other schyphozoa.
Common in the North Sea.