Cyclostoma
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Littorinimorpha
Family:	Pomatiidae
Genus:	Cyclostoma Lamarck, 1799
Type species
Turbo scalaris Linnaeus, 1758

Cyclostoma is an obsolete genus name of operculate snails with circular aperture.^[1]

This genus has become a synonym of Epitonium Röding, 1798

• Cyclostoma scalare (Linnaeus, 1758) (type species): synonym of Turbo scalaris Linnaeus, 1758 (original name), synonym of Epitonium scalare (Linnaeus, 1758)
• Cyclostoma elegans (O.F. Müller 1774): synonym of Nerita elegans O.F. Müller 1774 (original name), synonym of Pomatias elegans (O.F. Müller 1774)
• Cyclostoma acutum Draparnaud, 1805: synonym of Hydrobia acuta acuta (Draparnaud, 1805)
• Cyclostoma breve Draparnaud, 1805: synonym of Avenionia brevis (Draparnaud, 1805)
• Cyclostoma cincinnatiensis I. Lea, 1840: synonym of Pomatiopsis cincinnatiensis (I. Lea, 1840)
• Cyclostoma concinnum Scacchi, 1836: synonym of Truncatella subcylindrica (Linnaeus, 1767)
• Cyclostoma costulatum Rossmässler, 1837: synonym of Pomatias rivularis (Eichwald, 1829)
• Cyclostoma delicatum Philippi, 1844: synonym of Torellia delicata (Philippi, 1844)
• Cyclostoma gibbum Draparnaud, 1805: synonym of † Belgrandia gibba (Draparnaud, 1805)
• Cyclostoma lapidaria Say, 1817: synonym of Pomatiopsis lapidaria (Say, 1817)
• Cyclostoma marginatum Say, 1821: synonym of Pupoides albilabris (C. B. Adams, 1841)
• † Cyclostoma rubeschi Reuss in Reuss & Meyer, 1849 : synonym of † Staadtiellopsis rubeschi (Reuss in Reuss & Meyer, 1849)
• Cyclostoma subdisjuncta H. Adams, 1868: synonym of Tubiola subdisjuncta (H. Adams, 1868)
• Cyclostoma truncatulum Draparnaud, 1801: synonym of Truncatella subcylindrica (Linnaeus, 1767)