Cavinula maculata

Valves are elliptic-lanceolate with rounded apices. The valve face is flat, and at the margin, sharply bent onto the mantle. Striae are radiate throughout; a few shortened striae may be present around the central area. Striae are uniseriate and composed of fine, rounded to elliptic areolae. Internally, interstriae are slightly elevated and the areolae are covered with hymenes. The axial area is narrow and linear. The central area is large and circular or transversely elliptic. The central nodule is distinctly thickened on the internal side of the valve. The raphe is linear. Externally, the proximal and the distal raphe ends are pinhole-shaped. The distal raphe ends do not extend onto the valve mantle, that is, the raphe terminates on the valve face. Internally, the raphe is positioned on elevated sternum. Distal raphe fissures terminate with a helictoglossa. Copulae are open, with one row of pores.