Anterior region of carapace swollen; ventral margin slightly rounded, curving smoothly into rounded posterior margin (A. pilosa Habitus). Carapace tapers posteriorly, maximum height just posterior of rostrum. Right asymmetrical gland opens near mid-height on posterior margin, the left gland appears lacking. Striations intercept antero-ventral region below the incisure at an oblique angle. Male frontal organ stem only as long as first podomere of first antenna, capitulum which extends to just beyond end of limb, is slightly bent with rounded end carrying a minute spinule (A. pilosa 3). First antenna of male has five equal terminal setae which are broad and have pointed tips. The hook appendage on the left second antennal endopodite is short, thick and club-like (A. pilosa 4). The caudal furca has eight pairs of claw-setae.
Only the male has been described. Its length was given by Deevey as 1.35mm. Specimens taken in the North Atlantic have, tentatively, been ascribed to this species; all have been female around 1.0mm in length and damaged.
This is a rare bathypelagic species which is only known from the type locality, but Discovery Collection material contains specimens which fit Deevey's description well from 10°-49°N in the North Atlantic Ocean. 1 (R.R.S. Discovery Map).
Holotype, a male dissected on a slide. National Museum of Natural History, Smithsonian Institution (NMNH 171282).
32°10'N, 64°30'W Station "S" in the Sargasso Sea off Bermuda. Depth 1500-2000m; date 25 June 1969; Vertical tow.