Hi folks,

I was wondering if someone wouldn't mind taking the time to list the
different types of operculum present in the various gastropods, with a
short description of what they look like and what they're made of.   Just a
general idea, such as "type X is of Y material and looks like Z" and
perhaps "is present usually in XYZ species"...  please?  :)

Thank you, as always.

Nancy Smith