Detailed Product Description Concha Arcae Source:The shell of Arca granosa L., A. inflata Reeve, A. subcrenata ... Lischke, family Arcidae. Characteristics: Shell fan-shaped, convex at the back,top protruding and involute,3-9 cm long. Outer ... white, with 20-50 striae spreading from the top toward the edge, protruding or smooth at the striae, glabrous or with residual hairs .Inner ...