operculum defined in 1951 yearoperculum - operculum;
operculum - (1) Lid, e.g. of moss capsule, egg shell of fluke. (2) Cover of gill-slits of fish and Amphibia. (3) Exoskeletal plate of some gastropods, e.g. snail, which can close opening of shell when animal withdraws into the latter.
near operculum in Knolik
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