Shape elliptic with slightly convex medial face and flat lateral face. Dorsal depression deep, oblong. Dorsal margin and ventral margin entire. Irregular, slightly crenate, crenate at posterior margin. Sulcus ostial, deep. Ostium flared and cauda flared. Colliculum low, slightly raised in margin. Collum raised tubercle to solid bridge. Crista superior and crista inferior well-developed, both poorly-developed at posterior. Neck slightly dorso-ventrally constricted. Rostrum short, blunt. Excisura narrow. Notch shallow, angle acute.