• Arion A. Férussac, 1819
• Arion (Arion) A. Férussac, 1819 represented as Arion A. Férussac, 1819
• Arion (Arion) ater (Linnaeus, 1758) represented as Arion ater (Linnaeus, 1758)
• Arion (Arion) flagellus Collinge, 1893 represented as Arion flagellus Collinge, 1893
• Arion (Arion) franciscoloi Boato, Bodon & Fo. Giusti, 1983 (uncertain > taxon inquirendum)
• Arion (Arion) fuligineus Morelet, 1845 represented as Arion fuligineus Morelet, 1845
• Arion (Arion) lusitanicus Mabille, 1868 represented as Arion lusitanicus Mabille, 1868
• Arion (Arion) magnus Torres Mínguez, 1923 represented as Arion magnus Torres Mínguez, 1923
• Arion (Arion) rufus (Linnaeus, 1758) accepted as Arion ater rufus (Linnaeus, 1758)
• Arion (Arion) vulgaris Moquin-Tandon, 1855 represented as Arion vulgaris Moquin-Tandon, 1855
• Arion (Carinarion) P. Hesse, 1926 represented as Arion A. Férussac, 1819
• Arion (Carinarion) circumscriptus G. Johnston, 1828 represented as Arion circumscriptus G. Johnston, 1828
• Arion (Carinarion) circumscriptus circumscriptus G. Johnston, 1828 represented as Arion circumscriptus circumscriptus G. Johnston, 1828
• Arion (Carinarion) circumscriptus silvaticus Lohmander, 1937 represented as Arion circumscriptus silvaticus Lohmander, 1937
• Arion (Carinarion) fasciatus (Nilsson, 1823) represented as Arion fasciatus (Nilsson, 1823)
• Arion (Carinarion) silvaticus Lohmander, 1937 accepted as Arion circumscriptus silvaticus Lohmander, 1937
• Arion (Carinella) Mabille, 1870 accepted as Arion (Carinarion) P. Hesse, 1926 represented as Arion A. Férussac, 1819
• Arion (Carinella) subcarinatus Pollonera, 1885 (uncertain > unassessed)
• Arion (Kobeltia) Seibert, 1873 represented as Arion A. Férussac, 1819
• Arion (Kobeltia) alpinus Pollonera, 1887 accepted as Arion (Kobeltia) intermedius Normand, 1852 represented as Arion intermedius Normand, 1852
• Arion (Kobeltia) anthracius Bourguignat, 1866 represented as Arion anthracius Bourguignat, 1866
• Arion (Kobeltia) distinctus Mabille, 1868 represented as Arion distinctus Mabille, 1868
• Arion (Kobeltia) fagophilus de Winter, 1986 represented as Arion fagophilus de Winter, 1986
• Arion (Kobeltia) hortensis A. Férussac, 1819 represented as Arion hortensis A. Férussac, 1819
• Arion (Kobeltia) intermedius Normand, 1852 represented as Arion intermedius Normand, 1852
• Arion (Kobeltia) luisae Borrèda & Martínez-Ortí, 2014 represented as Arion luisae Borrèda & Martínez-Ortí, 2014
• Arion (Kobeltia) obesoductus P. L. Reischütz, 1973 represented as Arion obesoductus P. L. Reischütz, 1973
• Arion (Kobeltia) occultus R. Anderson, 2004 represented as Arion occultus R. Anderson, 2004
• Arion (Kobeltia) owenii S. M. Davies, 1979 represented as Arion owenii S. M. Davies, 1979
• Arion (Kobeltia) paularensis Wiktor & Parejo, 1989 accepted as Arion paularensis Wiktor & Parejo, 1989
• Arion (Kobeltia) timidus Morelet, 1845 represented as Arion timidus Morelet, 1845
• Arion (Kobeltia) vejdowskyi Babor & Koštál, 1893 accepted as Arion distinctus Mabille, 1868
• Arion (Kobeltia) wiktori Parejo & R. Martín, 1990 represented as Arion wiktori Parejo & R. Martín, 1990
• Arion (Letourneuxia) Bourguignat, 1866 accepted as Letourneuxia Bourguignat, 1866
• Arion (Letourneuxia) indifferens O. Boettger, 1884 † accepted as Geomalacus indifferens (O. Boettger, 1884) †
• Arion (Lochea) Moquin-Tandon, 1855 accepted as Arion A. Férussac, 1819
• Arion (Lochea) stabilei Pollonera, 1885 (uncertain > unassessed)
• Arion (Mesarion) P. Hesse, 1926 represented as Arion A. Férussac, 1819
• Arion (Mesarion) atripunctatus Dumont & Mortillet, 1853 represented as Arion atripunctatus Dumont & Mortillet, 1853
• Arion (Mesarion) baeticus Garrido, Castillejo & Iglesias, 1994 represented as Arion baeticus Garrido, Castillejo & Iglesias, 1994
• Arion (Mesarion) euthymeanus Florence, 1886 represented as Arion euthymeanus Florence, 1886
• Arion (Mesarion) fuscus (O. F. Müller, 1774) represented as Arion fuscus (O. F. Müller, 1774)
• Arion (Mesarion) gilvus Torres Mínguez, 1925 represented as Arion gilvus Torres Mínguez, 1925
• Arion (Mesarion) hispanicus Simroth, 1886 represented as Arion hispanicus Simroth, 1886
• Arion (Mesarion) iratii Garrido, Castillejo & Iglesias, 1995 represented as Arion iratii Garrido, Castillejo & Iglesias, 1995
• Arion (Mesarion) lizarrustii Garrido, Castillejo & Iglesias, 1995 represented as Arion lizarrustii Garrido, Castillejo & Iglesias, 1995
• Arion (Mesarion) molinae Garrido, Castillejo & Iglesias, 1995 represented as Arion molinae Garrido, Castillejo & Iglesias, 1995
• Arion (Mesarion) nobrei Pollonera, 1889 represented as Arion nobrei Pollonera, 1889
• Arion (Mesarion) paularensis Wiktor & Parejo, 1989 represented as Arion paularensis Wiktor & Parejo, 1989
• Arion (Mesarion) ponsi Quintana, 2007 represented as Arion ponsi Quintana, 2007
• Arion (Mesarion) simrothi Künkel, 1909 (uncertain > taxon inquirendum)
• Arion (Mesarion) subfuscus (Draparnaud, 1805) represented as Arion subfuscus (Draparnaud, 1805)
• Arion (Mesarion) transsylvanus Simroth, 1885 represented as Arion transsylvanus Simroth, 1885
• Arion (Mesarion) urbiae de Winter, 1986 represented as Arion urbiae de Winter, 1986
• Arion (Microarion) P. Hesse, 1926 represented as Arion A. Férussac, 1819
• Arion (Microarion) intermedius Normand, 1852 accepted as Arion intermedius Normand, 1852
• Arion (Microarion) obesoductus P. L. Reischütz, 1973 accepted as Arion obesoductus P. L. Reischütz, 1973
• Arion (Microarion) vejdowskyi Babor & Koštál, 1893 accepted as Arion distinctus Mabille, 1868
• Arion (Prolepis) Moquin-Tandon, 1855 accepted as Arion (Mesarion) P. Hesse, 1926 represented as Arion A. Férussac, 1819
• Arion alpinus Pollonera, 1887 accepted as Arion intermedius Normand, 1852
• Arion amygdaliformis Castillejo, Baselga, Lorenzo-Carballa, Iglesias & Gomez-Rodriguez, 2024
• Arion andersonii J. G. Cooper, 1872 accepted as Prophysaon andersonii (J. G. Cooper, 1872)
• Arion anguloi Martín & Gómez, 1988 accepted as Arion urbiae de Winter, 1986
• Arion anthracius Bourguignat, 1866
• Arion ascensionis R. P. Lesson, 1831 (uncertain > unassessed)
• Arion ater (Linnaeus, 1758)
• Arion ater ater (Linnaeus, 1758)
• Arion ater ruber (Garsault, 1764)
• Arion ater rufus (Linnaeus, 1758)
• Arion ater var. albida Roebuck, 1883 accepted as Arion ater (Linnaeus, 1758)
• Arion ater var. albolateralis Roebuck, 1883 accepted as Arion ater (Linnaeus, 1758)
• Arion ater var. empiricorum A. Férussac, 1819 accepted as Arion ater (Linnaeus, 1758)
• Arion aterrimus L. Pfeiffer & J. E. Gray, 1855 accepted as Oopelta aterrima (L. Pfeiffer & J. E. Gray, 1855)
• Arion atripunctatus Dumont & Mortillet, 1853
• Arion austeniana G. Nevill, 1880 (unaccepted > nomen nudum)
• Arion baeticus Garrido, Castillejo & Iglesias, 1994
• Arion bicolor Broeck, 1870 (uncertain > taxon inquirendum)
• Arion circumscriptus G. Johnston, 1828
• Arion circumscriptus circumscriptus G. Johnston, 1828
• Arion circumscriptus silvaticus Lohmander, 1937
• Arion circumscriptus var. silvaticus Lohmander, 1937 accepted as Arion circumscriptus silvaticus Lohmander, 1937
• Arion coerulens Collinge, 1897 accepted as Arion distinctus Mabille, 1868
• Arion cottianus Pollonera, 1889 accepted as Arion distinctus Mabille, 1868
• Arion distinctus Mabille, 1868
• Arion elongatus Collinge, 1894 accepted as Arion hortensis A. Férussac, 1819
• Arion empiricorum A. Férussac, 1819 accepted as Arion ater (Linnaeus, 1758)
• Arion euthymeanus Florence, 1886
• Arion fagophilus de Winter, 1986
• Arion fasciatus (Nilsson, 1823)
• Arion flagellus Collinge, 1893
• Arion flagellus var. phillipsi Collinge, 1893 (uncertain > unassessed)
• Arion foliolatus A. Gould, 1851 accepted as Prophysaon foliolatum (A. Gould, 1851)
• Arion fuligineus Morelet, 1845
• Arion fuscus (O. F. Müller, 1774)
• Arion fuscus var. pyrenaicus Moquin-Tandon, 1855 accepted as Arion hortensis A. Férussac, 1819
• Arion gilvus Torres Mínguez, 1925
• Arion hessei Simroth, 1894 accepted as Arion distinctus Mabille, 1868
• Arion hispanicus Simroth, 1886
• Arion hochheimensis Wenz, 1911 † (unaccepted)
• Arion hortensis A. Férussac, 1819