Radula hians var. transiens – synonym of Limaria hians
Ranella pygmaea – synonym of Nassarius pygmaeus
Raphitoma affinis – synonym of Bela nebula
Raphitoma boothi – synonym of Raphitoma leufroyi
Raphitoma brachystoma var. comitasensis – synonym of Bela brachystoma
Raphitoma intermedia – synonym of Raphitoma purpurea
Raphitoma lineolata fuscata – synonym of Raphitoma purpurea
Retusa carinensis – synonym of Retusa truncatula
Retusa mamillata – synonym of Retusa truncatula
Retusa plicata – synonym of Retusa obtusa
Retusa retusa – synonym of Retusa truncatula
Rhizorus acuminatus – synonym of Volvulella acuminata
Rhomboides rugosus var. aculeata – synonym of Hiatella arctica
Rissoa abyssicola – synonym of Alvania subsoluta
Rissoa albella – synonym of Pusillina sarsii
Rissoa albella – synonym of Rissoella diaphana
Rissoa alderi – synonym of Obtusella intersecta
Rissoa arctica – synonym of Onoba aculea
Rissoa brunosericea – synonym of Rissoa membranacea
Rissoa calatha – synonym of Alvania beani
Rissoa cerasina – synonym of Rissoa parva
Rissoa cimicoides – synonym of Alvania cimicoides
Rissoa cimicoides var. minima – synonym of Alvania cimicoides
Rissoa cingillata – synonym of Cingula trifasciata
Rissoa communis – synonym of Onoba semicostata
Rissoa diaphana – synonym of Rissoella diaphana
Rissoa ecostata – synonym of Onoba semicostata
Rissoa elata – synonym of Rissoa membranacea
Rissoa elegans – synonym of Melaraphe neritoides
Rissoa elegantissima – synonym of Alvania subsoluta
Rissoa elongata – synonym of Odostomia plicata
Rissoa fragilis – synonym of Rissoa membranacea
Rissoa fulva – synonym of Barleeia unifasciata
Rissoa glabra – synonym of Rissoella diaphana
Rissoa globosa – synonym of Obtusella intersecta
Rissoa graphica – synonym of Cingula trifasciata
Rissoa grossa – synonym of Rissoa membranacea
Rissoa inconspicua – synonym of Pusillina inconspicua
Rissoa intermedia – synonym of Alvania cimicoides
Rissoa interrupta var. bifasciata – synonym of Rissoa parva
Rissoa intersecta – synonym of Obtusella intersecta
Rissoa jeffreysi – synonym of Alvania jeffreysi
Rissoa lactea – synonym of Alvania lactea
Rissoa matoniana – synonym of Rissoa parva
Rissoa minutissima – synonym of Onoba semicostata
Rissoa multilineata – synonym of Onoba aculea
Rissoa oblonga – synonym of Rissoa membranacea
Rissoa obtusa – synonym of Obtusella intersecta
Rissoa opalina – synonym of Rissoella opalina
Rissoa peticularis – synonym of Onoba semicostata
Rissoa pontica – synonym of Rissoa membranacea
Rissoa porifera – synonym of Rissoa lilacina
Rissoa proxima – synonym of Onoba aculea
Rissoa punctata – synonym of Rissoa lilacina
Rissoa rufilabrata – synonym of Rissoa lilacina
Rissoa rufilabris – synonym of Rissoa lilacina
Rissoa rupestris – synonym of Cingula trifasciata
Rissoa sarsii – synonym of Pusillina sarsii
Rissoa saxatilis – synonym of Onoba aculea
Rissoa sculpta – synonym of Alvania cimicoides
Rissoa semicostulata – synonym of Rissoa parva
Rissoa soluta – synonym of Obtusella intersecta
Rissoa subsoluta – synonym of Alvania subsoluta
Rissoa tenuicostata – synonym of Alvania beani
Rissoa textilis – synonym of Alvania beani
Rissoa venusta – synonym of Rissoa membranacea
Rissoa vitrea – synonym of Hyala vitrea
Rissoa vulgatissima – synonym of Bittium reticulatum
Rissoella glabra conica – synonym of Rissoella diaphana
Rissoella inflata – synonym of Rissoella globularis
Rissostomia membranacea – synonym of Rissoa membranacea
Rossia glaucopis – synonym of Rossia palpebrosa
Rostanga perspicillata – synonym of Rostanga rubra
Rostanga rufescens – synonym of Rostanga rubra
Rostellaria serresiana – synonym of Aporrhais serresianus
Rostrisepta parva – synonym of Propilidium exiguum
Roxania utriculus – synonym of Roxania utricula
Runcina calaritana – synonym of Runcina coronata
Runcina hancocki – synonym of Runcina coronata
Rupicola concentrica – synonym of Thracia distorta