Onniella acuta Hints, 1975

Unequally biconvex shell with deep, subcarinate pedicle valve, about half as deep as long, and strongly convex and sulcate brachial valve. Dorsal adductor scars oval in outline, with anterior scars as long as posterior ones. Brachiophores subparallel with small socket plates. Radial ornamentation of isorthid type, consisting of fine costellae with counts of 4 per 2 mm, at 5 mm anterior of dorsal umbo.