Carapace appreciably narrowed anteriorly, surface and limbs with numerous small hook-setae often covered with encrusting growths of epifauna, frontal region produced into a narrow U-shaped, acute rostrum, each protogastric region with a tubercle; second and third peduncular segments of antenna slender; eyestalks totally visible in dorsal aspect. Second pereiopods thicker and longer than others. Female chelipeds small.
Male chelipeds much larger than in female, propodus long and slightly inflated, a truncate process sometimes present on inner margin of dactylus; sternum with a conspicuous tubercle.
Carapace length up to 21 (30) mm.
Depth range from lower shore (low water springtide) to about 165 metres on stone and shell substrates, less frequently on muddy sand; also on Modiolus beds to, Reported in Area from. Ovigerous crabs and larvae throughout year.
Carapace greyish or yellowish brown, chelipeds and pereiopods lighter.
Shetland, Sutherland, Viking, Orkney, Aberdeen, East Channel, Wight, Portland, Channel Isles, Plymouth, Bristol Channel, Isle of Man, Belfast, Clyde & Argyll, Galway Bay, Fastnet.