ioqua shell

from The Collaborative International Dictionary of English v.0.48

Ioqua shell \I"o*qua shell`\ [From the native name.] (Zool.)
   The shell of a large Dentalium ({Dentalium pretiosum}),
   formerly used as shell money, and for ornaments, by the
   Indians of the west coast of North America.
   [1913 Webster]