Simnia is a genus of sea snails, marine gastropod mollusks in the family Ovulidae. Taxonomy Dolin & Ledon (2002) considered that the lectotype of Simnia nicaeensis Risso, 1826, type species of Simnia, is a juvenile specimen of Simnia spelta (Linnaeus, 1758) type species of Neosimnia Fischer, 1884. This makes Simnia an objective synonym of Neosimnia. Accordingly, all the species treated in Lorenz & Fehse (2009) under Neosimnia should thereby be accepted under Simnia. Likewise, all the species treated by Lorenz & Fehse (2009) under Simnia should thereby be accepted under Xandarovula Cate, 1973. The assumptions of Dolin (Dolin & Ledon, 2002) are based on interpretations but not on the examination of the type material. Fehse (2016) has confirmed the vaility of the genus Neosimnia because the lectotype of Simnia nicaeensis Risso, 1826, type species of Simnia, is never a juvenile specimen of Simnia spelta (Linnaeus, 1758) type species of Neosimnia Fischer, 1884. Species The valid assignment of the taxa are found in Lorenz & Fehse, 2009. The assumption of Dolin prepared the following chaos: Species within the genus Simnia include: Simnia aequalis (Sowerby, 1832) Simnia aperta (Sowerby, 1849) Simnia arcuata (Reeve, 1865) Simnia avena (G.B. Sowerby I, 1832) Simnia barbarensis Dall, 1892 Simnia bartschi (Cate, 1973) Simnia bijuri (Cate, 1976) Simnia brevirostris (Schumacher, 1817) † Simnia fusulina Dolin & Lozouet, 2004 Simnia hammesi (Bertsch & Bibbey, 1982) † Simnia helenae Dolin & Lozouet, 2004 Simnia hiscocki Lorenz & Melaun, 2011 Simnia hyalina Lorenz & Fehse, 2009 Simnia illyrica (Schilder, 1925) Simnia jacintoi Fehse & Trigo, 2015 † Simnia lhommei (Cossmann, 1907) † Simnia limondinae Dolin & Lozouet, 2004 Simnia loebbeckeana (Weinkauff, 1881) Simnia macleani (Cate, 1976) Simnia patula (Pennant, 1777) † Simnia rostralina (Deshayes, 1865) Simnia sculptura (Cate, 1973) Simnia senegalensis (Schilder, 1931) Simnia spelta (Linnaeus, 1758) † Simnia vibrayana (de Raincourt, 1870) Simnia vidleri (Sowerby, 1881) Species brought into synonymy Simnia acicularis (Lamarck, 1811): synonym of Cymbovula acicularis (Lamarck, 1811) Simnia aequalis (G. B. Sowerby I, 1832): synonym of Neosimnia avena (G. B. Sowerby I, 1833) synonym of Simnia avena (G. B. Sowerby I, 1833) Simnia aureocincta Dall, 1899: synonym of Cyphoma aureocinctum (Dall, 1889) Simnia inflexa Schilder, 1941: synonym of Simnialena rufa (Sowerby, 1832) Simnia inflexa (Sowerby, 1832): synonym of Simnialena rufa (Sowerby, 1832) Simnia nicaeensis Risso, 1826: synonym of Simnia spelta (Linnaeus, 1758) Simnia nicaoensis Risso, 1826: synonym of Simnia nicaeensis Risso, 1826 Simnia piragua Dall, 1889: