Shape oval with slightly convex medial face and flat lateral face. Dorsal margin entire and ventral margin serrate, irregular and digitate. Tapering and sharply rounded at posterior margin. Sulcus ostio-pseudocaudal, deep. Ostium flared and cauda flared, rounded posteriorly. Colliculum low, higher in the cauda. Collum raised tubercle. Crista superior well-developed and crista inferior well-developed at neck, poorly-developed elsewhere. Neck slightly dorso-ventrally constricted. Rostrum short, broad, rounded. Excisura wide. Notch deep, angle wide.