A small, stout, rather equilateral Nucula, with a blunt umbo and usually with strong rounded concentric ribs and a very small chondrophore that does not project beyond the hinge plate. From Nucula praetenta (Iredale) it differs in its concentric ribs and possibly in its smaller size, and from Nucula saltator (Iredale) it differs in being shorter and more equilateral, in having a pronounced concentric sculpture over the whole valve beyond the interdissoconch and in the small non-projecting chondrophore.
DESCRIPTION: Valve stout, rather convex, triangular in outline, slightly longer than high. Umbo slightly opisthogyrate, bifid in juvenile valves. Anterior valve part relatively short. Dorsal margin rounded, passing without angulations into an almost straight posterior margin and a weakly curved anterior margin. Posteroventral angulation distinct but not sharp. Ventral margin but slightly curved posteriorly and more rounded anteriorly. Anteroventral angulation weak, not well marked. Embryonic shell with microscopic pits that under certain light give the impression of tube-like structures just under the shell surface (Bergmans, 1969). Interdissoconch small and smooth. Rest of valve usually with relatively strong, rounded concentric ribs, about as broad as their interstices. Narrow radial riblets between the concentric ribs except on anterior and posterior areas. Periostracum lost in the specimens studied. Shells transparent and white or shining yellowish brown. Chondrophore very small, triangular and oblique, separating the teeth rows but not projecting beyond hinge line. Up to 9 anterior and 6 posterior V-shaped secondary teeth. Only inner boundaries of adductor muscle scars visible. Pallial line not visible. Inner ventral margin denticulated by radial structure, with about 65 denticles in the figured specimen. Lectotype: Length 2.86; Height 2.66

Along the east coasts of Queensland and northern New South Wales, from Raine Island in the north to Port Stephens in the south, and in northern Western Australia