Body very robust, smooth. Coxal plate 1 tapering distally, plates 2 to 4 subquadrate. Epimeral plate 3 posterodistal angle obtuse, posterior margin straight and inset with numerous short setules. Head large; eyes rounded, black in colour. Antenna 1 reaching end of peduncle article 4 of antenna 2, flagellum about 7-articulate. Antenna 2 in male very robust, peduncle article 5 very much larger than 4, flagellum up to about 35-articulate; most articles of flagellum with distinct tooth on inner distal angle. Antenna 2 in female much shorter and less robust than in male. Gnathopod 1 simple, robust, strongly spinose, carpus elongate, propodus much shorter than carpus. Gnathopod 2 basis large, oval, carpus little longer than propodus in male, propodus of mitten-type. Pereiopods 5 to 7 robust, spinose; pereiopod 7 basis broadly expanded. Uropods 1 and 2 spinose; uropod 3 small, peduncle and ramus spinulose, apex of ramus with single large spine almost as long as the ramus. Telson entire, little broader than long, with several small dorsal and apical spines.
Up to 25 mm.
Usually found on sandy beaches amongst debris and decaying algae close to the high water mark; tends to be restricted to this level and extends little up or down the shore.
North East Atlantic; North Sea; widely recorded along European coasts from southern Norway to western Mediterranean and Azores.