Carapace suboval, broader than long, dorsal surface smooth to coarsely granular with minute, scattered, transverse carinae; frontal region produced anteriorly, median lobe advanced, submedians broadly rounded; outer ventral margin of orbit with a narrow incision. Antero-lateral margins of carapace with first and sometimes second teeth spatulate or subacute, second smaller than others, fifth acute and prominent. Chelipeds equal in size and stout, propodus longitudinally carinate; pereiopods moderately stout, carpus-dactylus of the second to fourth with longitudinal carinae, propodus with one longitudinal ventral carina extending length of margin (setose on second pereiopod) and a secondary inconspicuous distal carina extending at the most half the length of propodus; dactylus of second to fourth pereiopods styliform, of fifth broadly lanceolate and without a median carina. Male sixth abdominal segment noticeably longer than fifth.
Carapace length up to 10 (23) mm.
Depth range from intertidally to 100 metres, on sandy to stony bottoms. Ovigerous February-August, larvae January-July.
Very variable, carapace yellowish orange with brown banding on pereiopods, to a variegated brown and yellow; sometimes a broad median white or yellow band on carapace with pereiopods similarly banded.
Shetland, Orkney, Firth of Forth, Northumberland, Yorkshire, Wash, Thames, East Channel, Wight, Portland, Channel Isles, Plymouth, Scilly Isles, Bristol Channel, Anglesey, Liverpool Bay, Isle of Man, Dublin, Belfast, Clyde & Argyll, Minch, Mayo, Galway Bay, Fastnet, Cork.