Pilsbry Tusk Shell

Shell size to 26 mm; shell tubular, dull, chalky, or glossy. Nine evenly spaced ribs present, very rarely with an unevenly spaced tenth rib. Secondary ribs present, but not extending to apex (narrower end). Shell slightly curved. Compare with locally found Paradentalium americanum, which has six ribs instead of nine. Frequently found on Sanibel. (Entry prepared in cooperation with Rebecca Mensch.)