Shape fusiform, clamp-like. Dorsal depression shallow. Dorsal margin crenate and ventral margin serrate, emarginated, lobed. Sulcus ostial to caudal, indistinct at posterior tip, deep. Ostium very reduced and cauda flared, bulbous. Colliculum absent. Collum raised tubercle to wall-like. Crista superior ridge-like and crista inferior well-developed, both absent at posterior tip. Crista inferior thick, covered with crystalline granules. Neck dorso-ventrally constricted. Rostrum very extended, pointed. Excisura wide. Notch very deep.