Small, thin, rather oblique, white; dorsal margin sloping, posterior and ventral margins rounded, anterior margin sinuate, descending; prodissoconch of average size; sculpture about 22 sharp, narrow, radiating ribs, crowded posteriorly, apart medially and anteriorly, denticulate the margin, and are intersected by concentric riblets which produce erect scales at the point of contact and enclose nearly square meshes; within, the margin is narrow, especially anteriorly; the interlocking pits and tubercles upon it are slightly developed, especially anteriorly; in the posterior ventral angle three such are more prominent, from which ridges and furrows extend upwards into the valve; chondrophore oblique, submedian; byssal notch small; hinge crenulations well developed. Length 2 mm., height 2.5 mm., section 1.5 mm. Type locality: Cape Three Points, New South Wales, 41-50 fathoms.

South Australia. Beachport to Cape Wiles, 90-200 fathoms. S.A., Tas., Vict., N.S.W.