Shape elliptic to triangular with pointed postero-ventral tip. Convex medial face and concave lateral face. Dorsal margin entire and ventral margin serrate at anterior, entire elsewhere. Sulcus ostial, deep. Ostium flared and cauda elongate, straight, slightly flexed ventrally at posterior tip. Colliculum low. Crista superior and crista inferior well-developed, both absent at posterior end. Neck ventrally constricted. Rostrum extended, pointed. Excisura wide. Notch very shallow.