Sabinella (urchin-snails)
Saccostrea (rock-oysters)
Sagaminopteron (sea-slugs)
Sagenotriphora (sinistral-creepers)
Salaputium (thickshell-clams)
Salinator (air-breathers)
Sandalops (squids)
Sarepta (sareptas)
Sassia (rock-whelks)
Scalenostoma (coral-snails)
Scaphander (peanut-shells)
Scintillona (leptons)
Scissurella (slit-shells)
Sclerodoris (sea-lemons)
Scutellastra (limpets)
Scutus (elephant-snails)
Scyllaea (sea-slugs)
Seila (false-creepers)
Seilarex (dextral-creepers)
Selastele (top-shells)
Semicassis (helmets)
Semipallium (scallops)
Sepia (cuttlefish)
Sepiadarium (bottletail-squids)
Sepioloidea (dumpling-squids)
Sepioteuthis (calamari)
Serpulorbis (worm-shells)
Serracorbula (basket-shells)
Serrata (margin-shells)
Sigapatella (shelf-limpets)
Sinezona (slit-shells)
Sinum (sinums)
Siphonaria (siphon-shells)
Siphonochelus (murex-shells)
Siphopteron (sea-slugs)
Sirius (cap-shells)
Smeagol (smeagols)
Socienna (false-creepers)
Solamen (mussels)
Solatisonax (sundial-shells)
Solemya (date-shells)
Solen (razor-shells)
Soletellina (sunset-shells)
Spectamen (top-shells)
Specula (false-creepers)
Spirula (ramshorn-squids)
Spisula (trough-shells)
Splendrillia (turrids)
Spondylus (thorny-oysters)
Spurilla (sea-slugs)
Stenochiton (seagrass-chitons)
Stephopoma (worm-shells)
Stilapex (brittlestar-snails)
Stiliger (sea-slugs)
Stomatella (ear-shells)
Sunetta (venuses)
Sypharochiton (chitons)
Syrnola (pyramid-shells)