- Siriella thompsoni
- Siriella wolffi
- Sminthea eurygaster
- Solenolambrus brasiliensis
- Solenolambrus typicus
- Solenosphaera chierchiae
- Solenosphaera polysolenia
- Solenosphaera zanguebarica
- Solmaris corona
- Solmaris flavescens
- Solmissus atlantica
- Solmissus faberi
- Solmissus marshalli
- Solmundella bitentaculata
- Speloeophorus elevatus
- Speloeophorus nodosus
- Speocarcinus carolinensis
- Speocarcinus meloi
- Sphaeroidinella dehiscens
- Sphaeronectes gracilis
- Spinocalanus abyssalis
- Spinocalanus brevicaudatus
- Spinocalanus horridus
- Spinocalanus magnus
- Spirocyrtis scalaris
- Spirula spirula
- Spongaster tetras irregularis
- Spongaster tetras tetras
- Spongiobranchaea australis
- Spongiobranchaea intermedia
- Spongocore cylindrica
- Spongodictyon spongiosum
- Spongodiscus resurgens
- Spongoliva ellipsoides
- Spongoplegma antarcticum
- Spongoplegma rugosa
- Spongopyle setosa
- Spongosphaera streptacantha
- Spongotrochus glacialis
- Spongurus pylomaticus
- Spongurus spp.
- Stauracantha orthostaura
- Stauracantha spinulosa
- Stauracon pallidus
- Stauraspis echinoides
- Stauraspis stauracantha
- Stauraspis xiphacantha
- Staurocladia capensis
- Staurocladia hodgsoni
- Staurocladia vallentini