The Collaborative International Dictionary of English v.0.48:

Wing-shell \Wing"-shell`\, n. (Zool.)
   (a) Any one of various species of marine bivalve shells
       belonging to the genus Avicula, in which the hinge
       border projects like a wing.
   (b) Any marine gastropod shell of the genus Strombus. See
       Strombus.
   (c) Any pteropod shell.
       [1913 Webster]