Genus of snails found in marine, but more often in brackish, water. It has a long, many-whorled turreted shell, a short siphon, and a horny operculum (flap) to close the opening of its shell. It is also found abundantly as a fossil.

Classification
Cerithium is in family Cerithiidae, subclass Prosobranchia, class Gastropoda of phylum Mollusca.