Webster's Revised Unabridged Dictionary · 1913

Wing-shell

Wing-shell , noun

(a)
(Zoology) Any one of various species of marine bivalve shells belonging to the genus Avicula, in which the hinge border projects like a wing.
(b)
(Zoology) Any marine gastropod shell of the genus Strombus. See Strombus.
(c)
(Zoology) Any pteropod shell.