worm shell

noun

• 1a marine mollusc with a shell that forms loose irregular coils, giving it a worm-like appearance.

  • Family Vermetidae, class Gastropoda: Vermetus and other genera, including the European giant worm shell (V. gigas)

• 2the twisted calcareous tube of a sedentary marine bristle worm, typically attached to a stone or mollusc shell.

  • The worms belong to Serpula and other genera, class Polychaeta