| Raeta | Pteropsellinae | Mactridae | Mactroidea | Sinum | Sigaretinae | Naticidae | Naticoidea | |
| Ranella | Ranellinae | Ranellidae | Tonnoidea | Sinumelon | Cameninae | Camaenidae | Camenoidea | |
| Rangia | Mactrinae | Mactridae | Mactroidea | Siphocypraea | Bernayinae | Cypraeidae | Cypraeoidea | |
| Ranularia | Cymatinae | Ranellidae | Tonnoidea | Siphodentalium | Siphonodentaliidae | Gadilimorpha | Scaphopoda | |
| Ranularia | Cymatinae | Ranellidae | Tonnoidea | Siphonalia | Buccininae | Buccinidae | Buccinoidea | |
| Rapana | Rapaninae | Muricidae | Muricoidea | Siphonaliopsis | Siphopsinae | Conidae | Conoidea | |
| Raphitoma | Raphitominae | Conidae | Conoidea | Siphonaria | Siphonariidae | Siphonarioidea | ||
| Rastellum | Lophinae | Ostreidae | Ostreoidea | Siphonochelus | Typhinae | Muricidae | Muricoidea | |
| Raulinia | Pyramidellidae | Pyramidelloidea | Siphopsis | Siphopsinae | Conidae | Conoidea | ||
| Redicirce | Gafrarinae | Veneridae | Veneroidea | Siratus | Muricinae | Muricidae | Muricoidea | |
| Remera | Fusininae | Fasciolariidae | Columbelloidea | Sita | Astartinae | Astartidae | Astartoidea | |
| Remnita | Clavatulinae | Turridae | Conoidea | Skeneopsis | Skeneopsidae | Littorinoidea | ||
| Requienia | Requieniidae | Hippuritoidea | Smaragdia | Smaragdiinae | Neritidae | Neritoidea | ||
| Retusa | Retusidae | Bulloidea | Solamen | Crenellinae | Mytilidae | Mytiloidea | ||
| Rhinoclavis | Cerithiinae | Cerithiidae | Cerithioidea | Solariella | Solariellinae | Cirridae | Cirroidea | |
| Rhizorus | Retusidae | Bulloidea | Solariorbis | Vitrinellinae | Vitrinellidae | Rissooidea | ||
| Rhombostoma | Iravadiidae | Rissooidea | Solatia | Cancellariinae | Cancellariidae | Mitroidea | ||
| Rhynchostreon | Crassostreinae | Ostreidae | Ostreoidea | Solecurtus | Solecurtidae | Tellinoidea | ||
| Rhytida | Rhytidae | Rhytidoidea | Solemya | Solemyidae | Solemyoidea | |||
| Rillya | Strteptaxinae | Steptaxidae | Streptaxoidea | Solen | Solenidae | Solenoidea | ||
| Rimella | Strombinae | Strombidae | Stromboidea | Solena | Solenidae | Solenoidea | ||
| Rimula | Emarginulinae | Fissurellidae | Fissurelloidea | Solenosteira | Buccininae | Buccinidae | Buccinoidea | |
| Ringicula | Ringiculidae | Acteonoidea | Soletellina | Sanguinolariinae | Psammobiidae | Tellinoidea | ||
| Rissoa | Rissoinae | Rissoidae | Rissooidea | Solidula | Acteoninae | Acteonidae | Acteonoidea | |
| Rissoina | Rissoininae | Rissoinidae | Rissooidea | Solutofusus | Fusininae | Fasciolariidae | Columbelloidea | |
| Riuguhdrillia | Clathurellinae | Conidae | Conoidea | Sorgenfreispira | Mangeliinae | Conidae | Conoidea | |
| Roxania | Cylichnidae | Acteonoidea | Sowerbyceras | Phylloceratina | Ammonoida | |||
| Rubitrochus | Trochinae | Cirridae | Cirroidea | Spaniodontella | Kelliellidae | Glossoidea | ||
| Ruditapes | Tapetinae | Veneridae | Veneroidea | Spaniorinus | Galeommatidae | Galeommatoidea | ||
| Rupellaria | Petricolidae | Veneroidea | Spectamen | Solariellinae | Cirridae | Cirroidea | ||
| Saccella | Nuculaninae | Nuculanidae | Nuculanoidea | Spendrillia | Crassispirinae | Turridae | Conoidea | |
| Salinator | Amphibolidae | Amphiboloidea | Spengleria | Gastrochaenidae | Gastrochaenoidea | |||
| Sandbergeria | Diastomatinae | Diastomatidae | Cerithioidea | Sphenia | Spheniinae | Myidae | Myoidea | |
| Sanguinolaria | Sanguinolariinae | Psammobiidae | Tellinoidea | Spineilo | Nuculanidae | Nuculanoidea | ||
| Sargana | Sarganidae | Muricoidea | Spinifulgur | Busyconinae | Melongenidae | Buccinoidea | ||
| Sarmaturbo | Turbininae | Turbinidae | Trochoidea | Spiniscala | Epitoniinae | Epitoniidae | Janthinoidea | |
| Sassia | Cymatinae | Ranellidae | Tonnoidea | Spinomelon | Zidoninae | Volutidae | Volutoidea | |
| Saxidomus | Pitarinae | Veneridae | Veneroidea | Spinucella | Ocenebrinae | Muricidae | Muricoidea | |
| Saxolucina | Lucininae | Lucinidae | Lucinoidea | Spiradaphne | Daphnellinae | Conidae | Conoidea | |
| Scacchia | Lasaeinae | Lasaeidae | Galeommatoidea | Spirocolpus | Turritellinae | Turritellidae | Cerithioidea | |
| Scalaspira | Fusininae | Fasciolariidae | Columbelloidea | Spirulirostra | Spirulidae | Coleoida | ||
| Scalina | Epitoniinae | Epitoniidae | Janthinoidea | Spissatella | Crassatellinae | Crassatellidae | Crassatelloidea | |
| Scaliola | Scaliolidae | Cerithioidea | Spisula | Mactrinae | Mactridae | Mactroidea | ||
| Scalpomactra | Mactrinae | Mactridae | Mactroidea | Splendrillia | Drilliidae | Muricoidea | ||
| Scalptia | Cancellariinae | Cancellariidae | Mitroidea | Spondylus | Spondylidae | Pectinoidea | ||
| Scaphander | Cylichnidae | Acteonoidea | Sportella | Sportellidae | Cyamioidea | |||
| Scapharca | Anadarinae | Arcidae | Arcoidea | Staliola | Emmericiinae | Micromelaniidae | Rissooidea | |
| Scaphella | Scaphellinae | Volutidae | Volutoidea | Stazzania | Marginellinae | Marginellidae | Volutoidea | |
| Scaphellopsis | Scaphellinae | Volutidae | Volutoidea | Stenodrillia | Drilliidae | Muricoidea | ||
| Scapularca | Noetiinae | Noetiidae | Arcoidea | Stenothyra | Stenothyridae | Rissooidea | ||
| Schizobasis | Moreinae | Muricidae | Muricoidea | Stephopoma | Vermiculariinae | Turritellidae | Cerithioidea | |
| Scintilla | Galeommatidae | Galeommatoidea | Stewartia | Lucininae | Lucinidae | Lucinoidea | ||
| Scissurella | Scissurellidae | Scissurelloidea | Stigmaulax | Naticinae | Naticidae | Naticoidea | ||
| Scobinella | Clathurellinae | Conidae | Conoidea | Stilifer | Eulimidae | Eulimoidea | ||
| Sconsia | Cassinae | Cassidae | Tonnoidea | Stiracolpus | Turritellinae | Turritellidae | Cerithioidea | |
| Scrinium | Clathurellinae | Conidae | Conoidea | Stoliodoma | Pedipedinae | Ellobiidae | Ellobioidea | |
| Scrobricularia | Scrobiculariidae | Tellinoidea | Stomatella | Stomatellinae | Cirridae | Cirroidea | ||
| Scurria | Lottiinae | Lottiidae | Patelloidea | Stomatia | Stomatellinae | Cirridae | Cirroidea | |
| Scutus | Emarginulinae | Fissurellidae | Fissurelloidea | Straelenotrapezium | Trapeziidae | Glossoidea | ||
| Searlesia | Photinae | Buccinidae | Buccinoidea | Stramonita | Rapaninae | Muricidae | Muricoidea | |
| Sectipecten | Chlamydinae | Pectinidae | Pectinoidea | Strepsidura | Strepsidurinae | Olividae | Volutoidea | |
| Sedilia | Mangeliinae | Conidae | Conoidea | Streptochetus | Fasciolariinae | Fasciolariidae | Columbelloidea | |
| Sediliopsis | Drillidae | Muricoidea | Streptodictyon | Fusininae | Fasciolariidae | Columbelloidea | ||
| Seila | Cerithiopsinae | Cerithiopsidae | Ptenoglossa | Streptolathyrus | Fusininae | Fasciolariidae | Columbelloidea | |
| Sellia | Hydrobiinae | Hydrobiidae | Rissooidea | Striarca | Noetiinae | Noetiidae | Arcoidea | |
| Semele | Semelidae | Tellinoidea | Striatocostatum | Epitoniinae | Epitoniidae | Janthinoidea | ||
| Semelina | Semelidae | Tellinoidea | Strigatella | Mitrinae | Mitridae | Mitroidea | ||
| Semeloidea | Erycininae | Lasaeidae | Galeommatoidea | Strigilla | Tellininae | Tellinidae | Tellinoidea | |
| Semiauricula | Ellobiinae | Ellobiidae | Ellobioidea | Strioterebrum | Terebrinae | Terebridae | Conoidea | |
| Semicassis | Phaliinae | Cassidae | Tonnoidea | Striovertagus | Cerithiinae | Cerithiidae | Cerithioidea | |
| Semicorbula | Pachydontinae | Corbulidae | Myoidea | Strombiformis | Eulimidae | Eulimoidea | ||
| Semimodiola | Mytilinae | Mytilidae | Mytiloidea | Strombina | Pyreninae | Columbellidae | Columbelloidea | |
| Semineritina | Neritiinae | Neritidae | Neritoidea | Strombinella | Pyreninae | Columbellidae | Columbelloidea | |
| Seminolina | Helisomatinae | Planorbidae | Planorbioidea | Strombinophos | Photinae | Buccinidae | Buccinoidea | |
| Semistylifer | Stiliferidae | Eulimoidea | Strombolaria | Strombinae | Strombidae | Stromboidea | ||
| Semivertagus | Cerithiinae | Cerithiidae | Cerithioidea | Strombus | Strombinae | Strombidae | Stromboidea | |
| Septa | Cymatinae | Ranellidae | Tonnoidea | Struthiolaria | Struthiolariidae | Stromboidea | ||
| Septifer | Mytilinae | Mytilidae | Mytiloidea | Styliola | Clionae | Cavoliniidae | Spiratelloidea | |
| Seraphs | Seraphsidae | Stromboidea | Suavodrillia | Clathurellinae | Conidae | Conoidea | ||
| Serpula | Vermetidae | Vermetoidea | Subcancilla | Imbricariinae | Mitridae | Mitroidea | ||
| Serpulorbis | Vermetidae | Vermetoidea | Subepona | Cypraeinae | Cypraeidae | Cypraeoidea | ||
| Serrata | Marginellinae | Marginellidae | Volutoidea | Subpterynotus | Muricopsinae | Muricidae | Muricoidea | |
| Serratifusus | Fasciolariinae | Fasciolariidae | Columbelloidea | Subula | Terebrinae | Terebridae | Conoidea | |
| Serratocerithium | Cerithiinae | Cerithiidae | Cerithioidea | Suessionia | Buccininae | Buccinidae | Buccinoidea | |
| Serripecten | Chlamydinae | Pectinidae | Pectinoidea | Sulcoretusa | Retusidae | Bulloidea | ||
| Sigapatella | Calyptraeinae | Calyptraeidae | Calyptraeoidea | Sunetta | Sunettinae | Veneridae | Veneroidea | |
| Sigaretotrema | Sigaretinae | Naticidae | Naticoidea | Surculites | Peristerniinae | Fasciolariidae | Columbelloidea | |
| Sigatica | Polinicidae | Naticoidea | Sveltella | Cancellariinae | Cancellariidae | Mitroidea | ||
| Sigmesalia | Pareorinae | Turritellidae | Cerithioidea | Sveltia | Cancellariinae | Cancellariidae | Mitroidea | |
| Siliqua | Cutellinae | Pharidae | Tellinoidea | Sycostoma | Melongeninae | Melongenidae | Buccinoidea | |
| Siliquaria | Siliquariidae | Cerithioidea | Sydaphera | Cancellariinae | Cancellariidae | Mitroidea | ||
| Similipecten | Pectininae | Pectinidae | Pectinoidea | Syntomodrillia | Drilliidae | Muricoidea | ||
| Simnia | Ovulinae | Ovulidae | Cypraeoidea | Syrnola | Odostomellinae | Pyramidellidae | Pyramidelloidea | |
| Sinistrofulgur | Busyconinae | Melongenidae | Buccinoidea | |||||