Coxal plate 1 tapering distally, plate 2 rounded. Epimeral plate 3 posterodistal angle quadrate, acute. Eyes large, rounded, black in colour. Antenna 1 in male not reaching end of peduncle article 4 of antenna 2, flagellum about 6-articulate; antenna 1 in female reaching end of peduncle article 4. Antenna 2 in male variable, peduncle extremely robust especially article 5 of peduncle which may be twice length of article 4, flagellum up to about 20-articulate; antenna 2 in female much shorter and less robust. Antenna 2 flagellum, inner angle of each article with small tooth. Male gnathopod 1 spinose, carpus and propodus with small posterior lobe, palm short, dactylus longer than palm. Female gnathopod 1 carpus and propodus without posterior lobe, propodus simple, palm not defined, distal margin of propodus only slightly broader than base of dactylus. Male gnathopod 2 propodus extremely large and robust, palm with strong curved proximal process. Female gnathopod 2 carpus with asymmetrical posterior lobe, propodus of mitten-type. Pereiopods 5 to 7 robust. Uropod 3 ramus shorter than peduncle. Telson apically notched with several dorsolateral and apical spines.
Up to 15 mm.
Variable, brown, green or red, sometimes with darker spots or a longitudinal bands.
Burrows in fine sand on sheltered shores at about high tide level but may occur beneath stones beyond the range of the tides.
North-East Atlantic; North Sea; European coasts from Denmark to Mediterranean and Black Sea.