Memory is a funny thing

I was looking at something with my sons the other day and I got to thinking that I hadn't seen a particular type of marine life since we moved to Maryland. When I tried to describe this animal I said it was like a volcano and was some kind of mollusk.

Using Google images I figured out that it was in the limpet family and then today I finally figured out the thing is called a keyhole volcano limpet, which perhaps is why every time I see a volcano I'm reminded of it. I used to see loads of these on the beach when I was growing up but we don't seem to have them around here.