- scaphoconch
- seminal groove
- shell valve
- sinistral
- siphon
- siphonal canal
- siphonal fasciole
- siphonal notch
- siphonoplax
- slit band
- sole
- spatulate
- spawn
- spermatozeugma
- spicule
- spiculose
- spiral band
- spiral groove
- spiral ridge
- spiral striae
- spire
- squamate
- stellate
- streptoneurous
- stria
- styliform
- subsutural
- subsutural ramp
- sutural lamina
- suture
- symphyse