Triangularly ovate; apex sharply rounded, acute, terminal; dorsal margins almost straight and equal in length; periostracum fawn, shell white, translucent; faint accremental striae correspond with folds of the periostracum. Holotype: length 2 mm., height 2.6 mm. Robe. Specimens vary somewhat in comparative width. From N. ruber Hedley, it is fawn-coloured, not red, and has not the concave antero-dorsal margin.