Carapace appreciably narrowed anteriorly, surface and limbs with numerous small hook-setae usually concealed by dense encrusting growths of epifauna, frontal region produced as a wide U-shaped rostrum, postorbital spines large, meso- and protogastric regions spanned with four transversely placed spines or tubercles; second and third peduncular segments of antenna slender; eyestalks always totally visible from dorsal aspect. Second pereiopods conspicuously thicker than others. Female chelipeds small, propodus and dactylus somewhat compressed. Male chelipeds larger than in female, propodus short and inflated.
Carapace length up to 17 (35) mm.
Depth range from 4 to beyond 180 metres, on muddy, sandy, and rocky substrates. Ovigerous crabs and larvae throughout year.
Carapace reddish-brown, pereiopods lighter, underside of cheliped carpus of male bright pink or violet.
Shetland, Aberdeen, Firth of Forth, Northumberland, Yorkshire, Dogger, East Channel, Wight, Portland, Channel Isles, Plymouth, Scilly Isles, Cardigan Bay, Anglesey, Isle of Man, Dublin, Belfast, Clyde & Argyll, Minch, Mayo, Galway Bay, Fastnet, Cork.