Crown shell

(Zool.) See Acorn-shell.

See also: Crown

References in periodicals archive ?
The finale of Broxbourne Council's Millennium Music And Fireworks Spectacular is a 16-inch Brocade Crown Shell - the largest firework in the country - which will explode at 1,500ft.
A procedure for making fixed prosthodontic impressions with the use of preformed crown shells.