Disk Dosinia

Shell size to 65 mm; shell circular, compressed. Surface smooth. Sculpture of numerous concentric ridges, about 20 per cm in adults. Ligament internal, strong. Umbones well-developed. Lunule well-defined, heart-shaped. Periostracum thin, brown. Color white. Differs from Dosinia elegans by the larger number of concentric ridges. The specimen in the additional is "deformed," having a "squashed" (instead of circular) aspect to its outline. This deformity has most likely a genetic origin.