Cerithideopsis pliculosa, common name the plicate horn shell, is a species of sea snail, a marine gastropod mollusk in the family Potamididae.

It is genetically distinct from Cerithideopsis californica of the Pacific coast of the US.

The two species became isolated by the emergence of the Isthmus of Panama three million years ago.

DNA analysis suggests that there was some crossing of the Isthmus in both directions, and the common shorebirds called willets are suspected as carriers.

Willet droppings have been placed in dishes of salt water with the result that some snails hatched out.