Body rather broad and somewhat depressed. On the dorsal side of each segment of the body a more or less elevated conical projection; between the foremost projection and the ocular tubercle one of smaller size. The lateral processes of the body broad, nearly contiguous, each provided above with an obtuse knob.
Ocular tubercle rounded, with comparatively very small and widely spaced eyes. The proboscis about half the length of the body, rapidly tapering anteriorly, and with the outer part slender cylindrical. Chelifores and palps absent. The abdomen spatulate-expanded posteriorly, tip truncate.
Ovigerous legs in male cylindrical, having the four outer segments larger than the four inner, terminal claw powerfully developed and curving towards the extremity. Ovigerous legs absent in female.
Ambulatory legs shorter than the body, exceedingly powerful, with a rough, granulous skin; femur and first tibia largest, about equal in length, each with the extremity above taking the form of two obtuse projections; tarsus remarkably short, triangular, broader than the propodus, above almost concealed by the preceding segment; propodus slightly curved, scarcely at all tapering towards the extremity; terminal claw uncommonly powerful, more than half as long as the propodus, without an auxiliary claw.
Colour yellowish-white or brown. Length of the body in females, taken from the tip of the proboscis to the posterior end of the abdomen up to 15 mm; the extent between the points of the ambulatory legs reaching 26 mm. The males are generally somewhat smaller.
Littoral and sublittoral.
Widely distributed from the Arctic to Southern Spain.