(Boas, 1886)
Shell transparent, cross-section circular, surface with conspicuous transverse rings. With wing protrusions. Embryonic shell with anteriorly convex, posteriorly concave sides, blunt tip. Clear constriction separates embryonic from adult shells. Protoconch I is conical. Shell length 1.6 (exceptionally up to 2.7) mm, width 0.2 mm, embryonic shell 0.4-0.5 mm long.