Body thick and stout, with all the segments of the trunk coalesced. Lateral processes relatively shorter than in Achelia echinata , each furnished at the anterior end with a small setiferous process, and posteriorly with a strongly chitinised nodiform protuberance. Lateral corners of the cephalon less drawn out than in Achelia echinata . Cephalon massive, with an indistinct neck and a square frontal part. Ocular tubercle straight directed upwards, pyramidal, terminating in a conical point; the eyes situated nearly in the middle. Proboscis directed strongly downwards, about as long as the rest of the body. Chelifores somewhat more than half the length of the proboscis, the scape claviform, without any distinct dorsal process; the terminal segment irregularly oval in form. Palps with eight segments, 2nd segment shorter than the 4th, the latter about the same length as the terminal part.
Ovigerous legs present in both sexes, with 7-10 segments, relatively short, without a distinct terminal claw and with a very small number of serrated marginal spines.
Ambulatory legs hardly twice as long as the body, without distinct spines but with scattered setae; the first coxal segment furnished at the dorsal end with a nodiform process; all coxal segments in male rather densely setous; propodus somewhat swollen at the middle, strongly bent, and at the base furnished on the inner margin with three strong spines; terminal claw more than half the length of the propodus; auxiliary claws particularly small.
Length of the body up to 1.5 mm; the extent between the points of the ambulatory legs reaching 6 mm.
Sublittoral, often on algae and bryozoans.
This species is of wide occurrence and may be part of a large species-complex in the Northern Hemisphere, spreading from the Arctic almost to the Equator.