Aperture occupies virtually whole of interior face (left hand image).
1: recurved pointed umbo (rostrum) overhanging concave interior.
2: asymmetrical “ears” to either side of rostrum resemble scallop.
3: outer layer (periostracum) forms broad border beyond inner layer.
4: fractured calcareous inner-layer held in place by periostracum.
5: close-set concentric striae and a few indistinct radiating lines.
6: embayment on right side of shell.