Body with a central disc of up to 11 mm in diameter and 5 fine arms of about 8 times that length; coloured reddish or greyish-brown.
Disc covered with fine scales on both sides, those on the dorsal side gradually diminishing in size towards the edge of the disc. The primary plates are generally distinct; the radial shields are separated (A. chiajei disc).
The dorsal arm plates are rather fan-shaped, the ventral arm plates are hexagonal. There are 4-6 pairs of short, conical arm spines per segment. The tube foot pores are partially covered by 2 broad tentacle scales (A. chiajei arm).
The mouth shields are rhombic. There is a paired infradental papillae on top of the jaws and one broad, scale-like, outer mouth papilla on each side of the jaws, not contiguous with the infradental papillae. Two pairs of tube-feet within the mouth (A. chiajei mouth).
This species is found on muddy bottoms between 10-1000 m depth.
In the North Sea the species is reported from all British Isles usually below a depth of 10 metres.