Any of various species of marine bivalve shells formerly belonging to the no longer accepted genus Avicula, now a synonym of Pteria, with species assigned to several genera, in which the hinge border projects like a wing.

(zoology) A brachiopod (Brachiopoda).

Any of the marine gastropod mollusks of the genus Fasciolaria, especially Fasciolaria tulipa.

plural of tulip shell

plural of porcelain shell

A cowrie.

plural of spur-shell

Any of several species of conical gastropod shells in the family Trochidae and genus Astraea in family Turbinidae, the margin of the shells being toothed somewhat like the rowel of a spur.

Any species of Pleurotomaria, a genus of pearly spiral gastropod shells having a deep slit in the outer lip. Many fossil species are known, and a few living ones are found in deep water in tropical seas.

plural of slit-shell