Monogeneric.
Type genus: Acanthomenia Thiele, 1913
Distribution. -- Davis Strait (Antarctica) (A. gaussiana) and West European Basin (A. arcuata) from about 2,000 to 4,300 m.
Description. -- Elongate; epidermal spicules of three types: (1) upright, long, hollow, arranged from anteroventral to dorsoposterior; (2) adpressed, short, solid, arranged from dorsoanterior to ventroposterior beneath and at an angle to hollow spicules; (3) upright, solid spicules with basal rim; epidermis thick, cuticle thin; radula tiny, monostichous, teeth with a pair of two fused denticles; paired ventral, tubular salivary glands opening through single duct; midgut not sacculate, with dorsal coecum; lower gametoduct single; with a pair of single, tubular seminal receptacles; copulatory spicules lacking; respiratory gill-folds present; dorsoterminal sense organ perhaps absent.

From Ophelia 51 (1): 1-28 (1999).