Elliptic to oblong in shape with convex medial face and concave lateral face. Dorsal margin and ventral margin entire. Sulcus ostial, moderately
deep. Ostium flared. Cauda elongate, tube-like. Colliculum visible, undifferentiated, and raised only along its margin. Crista superior and crista
inferior well-developed. Antirostrum smaller than rostrum. Neck slightly constricted. Excisura wide.