Ferrissia

Ferrissia is a genus of small, air-breathing freshwater limpets, aquatic gastropod mollusks in the family Planorbidae, the ram's horn snails and their allies.

Species
Species within the genus Ferrissia include:
 * Ferrissia baconi (Bourguignat, 1853)
 * Ferrissia beaui (Bourguignat, 1853) - Beau's Stream Limpet
 * Ferrissia burnupi (Walker, 1912)
 * Ferrissia cawstoni Walker, 1924
 * Ferrissia ceylanica Benson, 1864
 * Ferrissia chudeaui Germain, 1917
 * Ferrissia clifdeni Connolly, 1939
 * Ferrissia connollyi (Walker, 1912)
 * † Ferrissia crenellata Harzhauser & Neubauer in Harzhauser et al., 2012
 * † Ferrissia deperdita (Desmarest, 1814)
 * † Ferrissia dimici (Brusina, 1902)
 * Ferrissia dohrnianus (Clessin, 1882)
 * Ferrissia eburnensis Binder, 1957
 * Ferrissia farquhari (Walker, 1924)
 * Ferrissia fontinalis (Walker, 1912)
 * Ferrissia fragilis (Tryon, 1863) - synonyms: Ferrissia clessiniana (Jickeli, 1882), Ferrissia wautieri (Mirolli, 1960) - Fragile Ancylid
 * Ferrissia gentilis Lanzer, 1991
 * † Ferrissia illyrica (Neumayr, 1880)
 * Ferrissia irrorata (Guilding, 1828)
 * Ferrissia isseli (Bourguignat, 1866)
 * Ferrissia junodi Connolly, 1925
 * Ferrissia kavirondica (Mandahl-Barth, 1954)
 * Ferrissia lacustris Walker, 1924
 * Ferrissia leonensis Connolly, 1928
 * Ferrissia lhotelleriei Walker, 1914 - dubious species
 * Ferrissia mcneili Walker, 1925 - hood ancylid
 * Ferrissia modesta Crosse, 1880
 * Ferrissia natalensis Walker, 1924
 * Ferrissia neozelanica (Suter, 1905)
 * † Ferrissia neumayri (Fontannes, 1881)
 * Ferrissia pallaryi Walker, 1914 - dubious species
 * Ferrissia parallela (Haldeman) - oblong ancylid or Ferrissia parallelus
 * Ferrissia petterdi (Johnston, 1879)
 * † Ferrissia pontileviensis (Morgan, 1920)
 * Ferrissia siamensis Brandt, 1974
 * Ferrissia rivularis (Say, 1817) - the type species
 * Ferrissia tasmanica (Woods, 1876)
 * Ferrissia tanganyicensis (Smith, 1906)
 * Ferrissia tenuis (Bourguignat, 1862)
 * Ferrissia toroensis (Mandahl-Barth, 1954)
 * † Ferrissia truci Wautier, 1975
 * Ferrissia verruca (Benson, 1855)
 * Ferrissia victoriensis (Walker, 1912)
 * Ferrissia viola (Annandale & Prashad, 1921)
 * Ferrissia walkeri (Pilsbry & Ferriss, 1907)
 * † Ferrissia wittmanni (Schlickum, 1964)
 * Ferrissia zambesiensis (Walker, 1912)
 * Ferrissia zambiensis Mandahl-Barth, 1968

Many specific names need revision, for example 11 species of Ferrissia in southern Africa.
 * Species brought into synonymy:
 * † Ferrissia senckenbergiana (Boettger, 1877): synonym of † Ferrissia deperdita (Desmarest, 1814)
 * Ferrissia wautieri (Mirolli, 1960) : synonym of Ferrissia fragilis (Tryon, 1836)
 * Ferrissia (Pettancylus) clessiniana (Jickeli, 1882) : synonym of Pettancylus clessiniana (Jickeli, 1882)