Carapace sub-triangular, dorsal surface with clusters of short hook-setae and often with thin encrusting growths of epizooites and epiphytes, frontal region produced as a bifid rostrum of moderate length each distal half diverging outwards, preorbital spine long, intercalary conspicuous, antorbital absent; second and third peduncular segments of antenna moderately broad, eyestalks stout, partly concealed when retracted. Antero-lateral margins of carapace with five spines, intestinal region with a small low tubercle or spine. Chelipeds equal in size; second to fifth pereiopods with suboval segments (in cross-section) and moderately stout, dactylus strongly curved terminally, inner margin with spines.
Male chelipeds larger than in female and broad, upper distal part of propodal prolongation often subtruncate.
Carapace length up to 25 (57) mm.
Depth range from 20 to 36 metres, often on Cystoseira. Ovigerous crabs April-May.
Carapace and pereiopods brownish.
Thames, East Channel, Wight, Portland, Channel Isles, Plymouth, Isle of Man, Mayo, Galway Bay, Fastnet, Cork.