Rostrum straight, with convex upper margin and apex often slightly upturned; about 1.5 x length of antennular peduncle; dorsal rostral teeth variable in number and extending posteriorly to about 0.66 x length of carapace, making an angle of about 20-25° with posterior border of carapace. Apex of rostrum normally an acute single point, with series of smaller teeth posterior and ventral to that point; ventral border convex. Inner basal part of eyestalk with tubercle.
Carapace with two supra-orbital spines, and antennal, branchiostegal and pterygostomian spines.
Stylocerite acutely pointed, about 0.75 x length of antennular peduncle.
Scaphocerite outer border very slightly convex, apical spine exceeding lamellar portion. Third maxilliped 1-1.25 x length scaphocerite; epipod and exopod present.
Mandible with molar and incisor process, and two-segmented palp.
Pereiopods 1-3 with epipods, reduced setobranch on pereiopod 4. Carpus of pereiopod 2 seven-segmented. Dactyli of pereiopods 3-5 slender, about 0.33 x length of propus. Pleonite 3 only slightly produced into a "hook" over pleonite 4. Small tooth on ventro-posterior border of pleonite 4.
Telson with three or four pairs of lateral spines.
Rostral shape is variable in this species: Dons (1915) and Greve (1963) figure other variations.
Length up to 74 mm, usually 40-60 mm.
Often bright red, occasionally dark red and frequently with white or yellowish spots on carapace and pleon.
Down to about 20-230 metres, although recorded as deep as 1200 metres. Hyperbenthic species, may swim up at night, mostly confined to the nepheloid layer. Ovigerous females occur from November to March-April.
Distribution in the North Sea:
Northern North Sea, Skagerrak.
Ranges from Greenland, Iceland and Spitzbergen south to the British Isles in the E Atlantic and from Delaware Bay northwards to the Davis Strait on the American Coast.