Hammer shell

(Zool.) any species of Malleus, a genus of marine bivalve shells, allied to the pearl oysters, having the wings narrow and elongated, so as to give them a hammer-shaped outline; - called also hammer oyster.

See also: Hammer

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
Well, there's the Hammer shell loaded with a miniature, ballistic nylon bag filled with tiny lead shot.
I am trying to find out where I can get more information on the "Dragon's Breath Hammer Shells." The article was in the September 2004 issue on page 70.