Oval to rounded trapezoidal in shape with pointed postero-ventral portion. Convex medial face and concave lateral face. Dorsal depression shallow, along crista superior. Dorsal margin slightly serrate and ventral margin entire. Sulcus ostial, deep. Ostium oblong, bended downward and cauda elongate, flexed ventrally at posterior. Colliculum low, large in ostium and protruded over excisura. Crista superior and crista inferior well-developed. Rostrum blunt, pointed at tip. Excisura wide. Notch shallow.