opercula

1.【植】果盖;藓盖;【动】螺的厣;(鱼的)鳃盖骨;【虫】盖

1.the plug of mucus that fills the opening of a woman's cervix while she is pregnant.

2.the flexible bony flap covering the gills of bony fishes

3.a flap covering an aperture in the spore capsules of mosses and some fungi

4.a rounded plate that seals the mouth of the shell of some gastropod mollusks when the animal's body is inside