Shape square, dumpling-Shaped. Dorsal depression deep, fan-shaped. Dorsal margin irregular, large crenate and ventral margin approximately entire. Sulcus mesial, shallow. Ostium bifid with sharply rounded antero-ventral corner, downward. Cauda elongate, tube-like and slightly upward at posterior tip. Colliculum high. Crista superior and crista inferior poorly-developed, thick and swelling. Neck slightly constricted. Rostrum absent. Excisura absent. Notch absent.