This, the largest species of the genus so far known, is the Recent descendant of the mid-Pliocene dictyota. That species has narrow, sharply raised spirals and axials, producing an open fenestrate effect. The Recent species is wider, with the axials more bluntly rounded, 12 on the body-whorl, and the primary spirals reduced to two, the third being immersed by the succeeding whorl. Secondary spirals close-spaced, fine but distinct. Colour pale-buff. Pillar and fasciole tinged with purplish-brown, and two similarly coloured faint bands within the aperture.
Height, 7.8 mm.; diameter, 3.2 mm. (Holotype). Holotype in writer's collection, Auckland Museum.
Localities: Tryphena Bay, 6 fath., Great Barrier Id. (type); Foveaux Strait, 15 fath.; Lyall Bay, Wellington.