As Semele tabogensis Pilsbry & Lowe:
The shell is thin, orange, shading through pink into light coral red near the umbones; very shortly oval, strongly compressed, slightly inequilateral. The broadly rounded anterior end is somewhat lower than the posterior end which is noticeably truncate. Dorsal margin somewhat concave in front of the beaks, convex behind them. In the right valve these margins are produced towards the other valve, covering the ligament. Ventral margin strongly convex. Sculpture of regular, recurved concentric riblets, which become laminar near the dorsal margin, and are somewhat darker colored than their intervals, in which fine, weak, radial striation is seen. Beaks smooth. Lunule extremely small, confined to the right valve. The interior varies in color from carnelian red to apricot orange, smooth, with some scattered glossy dots. Teeth are lighter or whitish in large individuals. Anterior lateral short, the posterior long and thinner. The pallial sinus reaches well past the middle. Length 37.5 mm., height 30.3 mm., semidiam. (right valve) 6.5 mm. Taboga Island, among rocks near the bathing beach. The very compressed form, beautiful color and strong, sharp sculptured are characteristic and unlike any species we have been able to compare.