Originally described as "Helix perversus" by Linnaeus in 1758, "Amphidromus perversus" is the type species of the genus "Amphidromus", by the subsequent designation of Eduard von Martens (1860). Species in the subgenus "Amphidromus" are amphidromine (left-handed and right-handed snails occur within the population) with a few exceptions. Four dextral taxa are: "A. givenchyi", "A. protania", "A. schomburgki dextrochlorus" and "A. inversus annamiticus"; and one sinistral: "A. atricallosus classiaris". These species usually have shells which have ht following characteristics: they are large (height often exceeding ); they have a height/width ratio of less than 1.85; and a shell color which is yellowish or greenish. Anatomically they have a long epiphallus and flagellum, and an appendix is usually present.