Shell of the Week: The Common Sundial
Architectonica nobilis (Röding, 1798) is a marine snail of the sundial family Architectonicidae that may reach in excess of 50 mm (about 2 inches) in diameter. The characteristic, circular, shield-like shell has a sculpture of strong spiral ribs crossed by axial cords, and reddish-brown spots superimposed on a light-cream background. The umbilicus (“hole” on the base) is deep and internally flanked by a wide, segmented band. The species has a very broad distribution from North Carolina to Florida and the Caribbean, Gulf of Mexico (in deeper water), and both sides of the tropical Atlantic Ocean, including West Africa.