Shell medium, thin, compressed, fragile, elongated with both ends rounded. Umbones towards the anterior end, low scarcelyprojecting about hinge line. Exterior ornamented by fine concentric growth lines. A deep triangular pit or notch below the inner side of the umbo, Pallial sinus broad and deep. Inner margin sharp. Colour: outside light purplish-grey, thin brownish periostracom. Interior white.