Dodatak:Popis mekušaca, Or
Or uredi
- Orania
- Orbitestella
- Orbitestellidae
- Ordtrachia
- Orectospira
- Oreokera
- Oreomava
- Orientalia
- Orientalina
- Orinella
- Ornatoconcha
- Ornithoteuthis
- Orobitella
Orpiella Gray, 1855 uredi
- Orpiella compluviata (Cox, 1871)
- Orpiella cookensis Gould
- Orpiella fragillima Gould
- Orpiella godeffroyana Garrett, 1872
- Orpiella mouelti Kae
- Orpiella nouleti (Le Guillou, 1842)
- Orpiella pfeifferi (Philippi, 1845)
- Orpiella scorpio Gould
- Orpiella solidiuscula (Smith, 1885)
- Orpiella tenella Garrett, 1872
Mollusca → Gastropoda → Pulmonata → Helicarionoidea → Helicarionidae → Helicarioninae
Podrod Orpiella (Irenella) Gude, 1913 uredi
- Orpiella (Irenella) hoyti Garrett, 1872
- Orpiella (Irenella) otareae Garrett
Mollusca → Gastropoda → Pulmonata → Helicarionoidea → Helicarionidae → Helicarioninae
Orpiella (Owaraha) Baker, 1941 uredi
- Orpiella (Owaraha) nissani Dell, 1955
Mollusca → Gastropoda → Pulmonata → Helicarionoidea → Helicarionidae → Helicarioninae
- Orrmaesia
- Orthalicoidea
- Orthoyoldia