Ancylus (Ancylastrum) capuloides Jan, 1838 accepted as Ancylus capuloides Jan, 1838 (basis of record)
Ancylus (Ancylastrum) expansilabre Clessin, 1880 accepted as Ancylus expansilabris Clessin, 1880 (basis of record)
Ancylus (Ancylastrum) fluviatile O.F. Müller, 1774 accepted as Ancylus fluviatilis O. F. Müller, 1774 (basis of record)
Ancylus (Ancylastrum) fluviatile var. subcirculare Clessin, 1880 accepted as Ancylus subcircularis Clessin, 1880 (basis of record)
Bythinella (Hungarica) Clessin, 1890 accepted as Bythinella Moquin-Tandon, 1856 (original description)
Bythinella (Lemanica) Clessin, 1890 accepted as Bythinella Moquin-Tandon, 1856 (original description)
Bythinella (Lemanica) brotiana Clessin, 1890 accepted as Bythinella pupoides (Paladilhe, 1869) (original description)
Bythinella alta Clessin, 1890 accepted as Bythinella bavarica Clessin, 1877 (original description)
Bythinella robici Clessin, 1890 accepted as Sadleriana robici (Clessin, 1890) (original description)
Clausilia (Alopia) regalis var. deubeli Clessin, 1890 accepted as Alopia regalis deubeli (Clessin, 1890) (original description)
Hyalina opinata Clessin, 1887 accepted as Mediterranea inopinata (Uličný, 1887) (original description)
Limax (Bielzia) Clessin, 1887 accepted as Bielzia Clessin, 1887 (original description)
Limnaea (Gulnaria) auricularia var. moratensis Clessin, 1889 accepted as Radix auricularia (Linnaeus, 1758) (original description)
Limnaea (Gulnaria) ovata var. godetiana Clessin, 1889 accepted as Ampullaceana lagotis (Schrank, 1803) (original description)
Limnaea (Gulnaria) ovata var. hasta Clessin, 1889 (original description)
Limnaea (Gulnaria) ovata var. hazayana Clessin, 1889 accepted as Ampullaceana balthica (Linnaeus, 1758) (original description)
Limnaea (Gulnaria) peregra var. acutispirata Clessin, 1889 accepted as Ampullaceana fontinalis (S. Studer, 1820) (original description)
Limnaea (Gulnaria) peregra var. albomarginata Clessin, 1889 accepted as Ampullaceana balthica (Linnaeus, 1758) (original description)
Limnaea (Gulnaria) peregra var. blauneri (Küster, 1862) accepted as Peregriana peregra (O. F. Müller, 1774) (basis of record)
Limnaea (Gulnaria) peregra var. cinerea Clessin, 1889 accepted as Ampullaceana balthica (Linnaeus, 1758) (original description)
Limnaea (Gulnaria) peregra var. lacustris Clessin, 1889 accepted as Peregriana peregra (O. F. Müller, 1774) (original description)
Limnaea (Lymnus) stagnalis var. charpentierii Clessin, 1889 accepted as Lymnaea stagnalis (Linnaeus, 1758) (original description)
Lithoglyphus (Sadleriana) Clessin, 1890 accepted as Sadleriana Clessin, 1890 (original description)
Lithoglyphus (Sadleriana) globulus Clessin, 1890 accepted as Bythinella robiciana (Clessin, 1890) (original description)
Lithoglyphus (Sadleriana) robicianus Clessin, 1890 accepted as Bythinella robiciana (Clessin, 1890) (original description)
Orcula brancsikii Clessin, 1887 accepted as Orcula dolium brancsikii Clessin, 1887 (original description)
Orcula branisikii accepted as Orcula dolium brancsikii Clessin, 1887 (basis of record)
Pisidium loveni Clessin, 1890 accepted as Pisidium casertanum (Poli, 1791) accepted as Euglesa casertana (Poli, 1791) (original description)
Pomatias (Obscurella) Clessin, 1889 accepted as Obscurella Clessin, 1889 (original description)
Sphyradium parreyssii var. armata Clessin, 1887 accepted as Agardhiella armata (Clessin, 1887) (original description)
Sphyradium parreyssii var. lamellata Clessin, 1887 accepted as Agardhiella lamellata (Clessin, 1887) (original description)
Valvata (Tropidina) imhofi Clessin, 1890 (original description)
Valvata (Tropidina) profunda Clessin, 1890 accepted as Valvata piscinalis (O. F. Müller, 1774) (original description)
Vitrella haeussleri Clessin, 1890 accepted as Bythiospeum haeussleri (Clessin, 1890) (original description)
Vitrella pfeifferi Clessin, 1890 accepted as Bythiospeum pfeifferi (Clessin, 1890) (original description)
Xerophila jachnoi Clessin, 1890 (original description)