| Sự chẩn đoán |
Shell solid, medium sized, higher than long, elongate-ovate in outline. Both valves convex, the right (lower) valve more inflated than the left (upper) valve. Ears subequal in size and shape. Right anterior ear with a slight byssal notch anteroventrally, devoid of ctenolium. Outer sculpture of about 10 or 11 rounded radial folds (9 to 13) on each valve, with numerous, much smaller, secondary radial riblets that are set with densely and finely imbricated transverse scales, giving a rather strongly scabrous aspect. Surface of ears with distinct radial ridges (more developed on right anterior ear). Hinge line quite long, about 2/3 of shell length, with shallow marginal ridges. Interior of valves shiny, with a flattened radial sculpture corresponding with the outer folds. Colour: outside of shell off-white to interior satin white, with dark brown on the hinge line. |
