Carapace suboval, much broader than long, dorsal surface moderately convex with minute transverse (sometimes setose) carinae; margin of frontal region entire and setose; outer ventral margin of orbit with a narrow incision. Antero-lateral margin of carapace with teeth alternating slightly in size, fourth smallest and sometimes almost obsolete. Chelipeds equal in size and relatively smooth, propodus with longitudinal (usually obtuse) carinae; pereiopods moderately stout, carpus-dactylus of second to fourth with longitudinal carinae, propodus with one setose, longitudinal ventral carina extending whole length of margin and a secondary obsolete shorter one distally, dactylus styliform; dactylus of fifth pereiopod broadly lanceolate with very indistinct median carina.
Carapace length up to 19 (29) mm.
Depth range up to 70 metres, on gravel and sand. Ovigerous April-September; larvae spring-August.
Carapace dark brown, pereiopods lighter.
Orkney, Yorkshire, Wash, Thames, East Channel, Wight, Portland, Channel Isles, Plymouth, Scilly Isles, Bristol Channel, Liverpool Bay, Isle of Man, Dublin, Belfast, Clyde & Argyll, Donegal Bay, Mayo, Galway Bay, Fastnet, Cork.