DIAGNOSIS: A very small species of Nucula, with minute radial striae on parts of interdissoconch, radial and concentric riblets on dissoconch, a small chondrophore, and a finely denticulated inner ventral margin. Differs from Nucula mayi (Iredale) and Nucula covra Bergmans by its radial interdissoconch striae, by the presence of radial riblets on anterior and posterior dissoconch parts and by the relatively small space between chondrophore and secondary teeth rows. From N. covra it differs moreover by the narrowness of the radial riblets.

DESCRIPTION: Valve small, relatively solid, somewhat inflated, squarish ovate in outline. Dorsal margin curved, with almost straight anterior and posterior parts. Anterodorsal and posterodorsal angulations marked. Posterior side short, truncated. Posteroventral angulation not sharp but distinct. Anterior side slightly bent, with broad curve passing into rather evenly rounded ventral side. Embryonic shell bifid, with microscopically pitted surface. Interdissoconch with very delicate radial striae, especially on anterior, posterior and ventral areas, and with fine growth lines. Dissoconch with narrow, evenly spaced radial riblets, definitely not corresponding with striae on interdissoconch. These riblets are about as broad as their interstices, extending on anterior and posterior areas, numbering over 70 near valve margin in holotype. The concentric riblets on the dissoconch are somewhat stronger, and less regularly arranged, than the radial riblets. Periostracum unknown, shell whitish. Hinge without distinct primary teeth, dorsal margin not thickened near chondrophore. Up to 6 anterior and 5 posterior secondary teeth, median ones rather crowded and very close to chondrophore. Adductor muscle scars ovate, pallial line indistinct. Inner ventral margin finely denticulated by radial dissoconch structure. Holotype: Length: 1.04 Height: 0.90

The known range reaches only from Narrabeen to Middle Harbour, Port Jackson, New South Wales