Cerithidia

Cer·i·thid·ia (ser″ĭ-thidґe-ə) a genus of spiral-shelled snails of the family Cerithiidae, subclass Streptoneura, found in brackish water in tropical and subtropical areas. C. cingulaґta is a Japanese species that is the chief intermediate host for the trematode Heterophyes heterophyes.