Operculum
/oʊˈpɝ.kjə.ləm/
"Operculum" in a Sentence (2 examples)
Hyoliths […] have a small, conical calcium carbonate shell, with a lid called an operculum.
I lifted the circular operculum from its place and laid it carefully on the bale.
Hyoliths […] have a small, conical calcium carbonate shell, with a lid called an operculum.
I lifted the circular operculum from its place and laid it carefully on the bale.