Trapezoidal, elongate in shape with longer dorsal side. Dorsal depression deep, grooved. Convex medial face along with concave lateral face. Dorsal margin entire and ventral margin serrate. Sulcus covers large proportion of surface, para-ostial, which ostial canal opening to the dorsal corner. Ostium small at anterior tip, gradually wider, widest at neck. Cauda elongate, slightly flexed at tip. Colliculum raised, crystalline, covers all but the extremes of sulcus. Crista superior and crista inferior well-developed. Neck slightly constricted. Rostrum very small, very pointed. Excisura very narrow if exist.
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