Shape ovate, approximately rectangular with convex medial face and concave lateral face. Dorsal depression deep, along crista superior. Dorsal margin and ventral margin creanate, dentate. Sulcus ostial, deep. Ostium oblong and cauda elongate, markedly flexed ventrally at posterior. Colliculum large, bulbous dorsally and extended over excisura in ostium. Collum raised. Crista superior and crista inferior well-developed. Rostrum blunt, large. Excisura wide. Notch deep, interrupted.