| Diagnose |
Shell solid, small, nearly as long as high, inequivalve, the outline somewhat elongate dorsally and subcircular ventrally. Both valves convex, the right (lower) valve more inflated than the left (upper) valve which is moderately flattened towards the umbo. Ears small, subequal in size and shape. Right anterior ear with an obsolete anteroventral byssal notch, devoid of ctenolium. Outer sculpture of each valve with about 9 to 11 rounded radial folds, with numerous, much smaller secondary radial riblets that are finely lamellous on ribs or interspaces; transverse lamellous sculpture delicate and easily eroded on top of ribs. Hinge line short, about 1/3 to 1/2 of shell length, with rather strong oblique ridges and pits on either side of internal ligament. Interior of valves shiny , with a flattened radial sculpture corresponding with the outer folds. Colour: outside of shell off-white to beige, variously mottled with chestnut brown, tan or reddish purple, mainly on the left valve which is more vividly coloured than the often nearly uniform cream right valve. Interior whitish, frequently tinged with dark brown on hinge areas and broad rims, in 1 or both valves. |