Coxal plate 1 moderately produced anteriorly and acute. Antenna 1 peduncle article 2 longest, flagellum up to about 22-articulate; accessory flagellum 2-articulate, with article 2 minute. Antenna 2 about two-thirds of the length of antenna 1, peduncle articles 4 and 5 about equal, flagellum shorter than the peduncle article 5, about 9-articulate. Male gnathopod 1 basis short and broad, carpus greatly expanded, posterodistal margin with two to four short teeth of which the distal tooth is the longest, propodus short with the posterior margin sinuous, dactylus robust. Female gnathopod 1 basis moderately expanded, propodus slightly longer than the carpus. Male gnathopod 2 basis broadly expanded with the anterior margin weakly crenulate, carpus and propodus about equal in length. Female gnathopod 2 basis with anterior margin crenulate, merus, carpus and propodus with a few plumose setae on the anterior margins, merus reaching about half the length of the carpus, propodus width to length ration about 1:3. Pereiopods 3 and 4 basis weakly expanded. Pereiopods 5 to 7 elongate, slender, spinose. Telson with the distal angles acute, each crest with small group of dorsal setae.
Up to about 10 mm.
Greenish white, with small brown patches on the dorsal surface.
Intertidal amongst algae, often in rock pools, eel-grass beds and in salt marshes; subtidally to depths of 150 metres, always associated with rich detritus.
North Atlantic; American and European coasts; from the south Baltic to the Mediterranean and Black Sea.