from The Century Dictionary and Cyclopedia
- n. A mussel-shell of the stone-boring genus Lithodomus (or Lithophagus), of the family Mytilidæ, as the Mediterranean L. dactylus, abounding in the subaqueous columns of the temple of Serapis at Pozzuoli, near Naples: so called from its shape or appearance. See Lithodomus.
Sorry, no etymologies found.
The one called the date-shell can, assisted by its liquid acid, pierce the hardest stone with its cylindrical gimlet.