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Southwest Florida Shells with Emphasis on Sanibel & Captiva

By José H. Leal

Family Potamididae

Cerithideopsis costata

(E.M. da Costa, 1778)

Costate Horn Snail

Shell size to 15 mm; shell with twelve rounded whorls and well-defined suture. Sculpture of low, rounded axial ribs that decrease in size on two last whorls. Outer lip flaring. Color light- to dark-brown with spiral bands of lighter color.