What is "cyclostoma"

Cyclostomata \Cy`clo*stom"a*ta\ (s?`kl?-st?m"?-t?), ||Cyclostoma \Cy*clos"to*ma\ (s?-kl?s"t?-m?), n. pl. [NL., fr. Gr. ky`klos circle + sto`ma, -atos mouth.] (Zo["o]l.) A division of Bryozoa, in which the cells have circular apertures.

Cyclostoma is an obsolete genus name of operculate snails with circular aperture.

This genus has become a synonym of Epitonium Röding, 1798