Shape elliptic with slightly convex medial face and flat lateral face. Dorsal margin entire and ventral margin slightly serrate. Tapering, sharply rounded at posterior margin. Sulcus ostio-pseudocaudal, deep. Ostium flared and cauda oblong, approximately straight, slightly bulbous posteriorly. Colliculum low. Collum raised tubercle. Crista superior and crista inferior well-developed. Neck dorso-ventrally constricted. Rostrum short, rounded. Excisura wide. Notch shallow, angle wide.