Disk Dosinia
Dosinia discus (Reeve, 1850)
Family Veneridae
The Disk Dosinia are rarely found on S. Hutchison beaches. Here are two from my collection found in 2020:
The Disk Dosinia is a thin flat shell usually white or off-white with concentric circles extending around its beak. This shell is related to the Elegant Dosinia, Dosinia concentrica. The two species have shells that are very similar in size (about 2.75–3 inches), in their circular shape, and white color, but the Disk Dosinia differs from its “sister species,” above all, by having twice as many commarginal (“concentric”) ridges, about 16–20 per centimeter (40–48 per inch).