Shell small, inflated, white, with a very thin pale dehiscent epidermis; sculpture of rather coarse, somewhat irregular concentric lines and grooves, in harmony with the incremental lines; beaks high, stout, inflated; shell almost exactly the shape of Cytherea albida; lunule short, wide, marginated by a distinct groove; ligament short, wholly external; escutcheon none, or undefined by any ridge; anterior end rounded, posterior end slightly more pointed ; interior white smooth, the muscular scars faint, the pallial line simple, indistinct; teeth in the left valve two; one representing the fused middle and anterior tooth is formed by the ventral margin of the hinge-plate projecting laterally in a squarish elongate lamina showing two short curves concave downward and meeting each other at a slight ridge, at the termination of which is a small indentation in the profile of the lamina; the other tooth is close to the dorsal side of the hinge-plate, wholly separated from the other lamina, than which it is lower and less curved; it lies directly under the ligament; altitude of shell 8; longitude 9; diameter 7MM.

A single left valve was obtained. This species is quite near Protocallithaca adamsi from Sierra Leone, but has fuller and stouter beaks and a more elongated and Cytherea-like outline; the lunule is also smaller and proportionately broader; the teeth differ in small details, being stout and curved, not flat and low as in the typical Vesicomya.

Brazil. East of Rio de Janeiro.