Smallest Shell in the World?

Okay, so I don't really think its the smallest shell in the world, but it is pretty darn small. I found this shell in Ireland, in 1983, while I was visiting with my parents. My Mom is from Trafrask, County Cork, Ireland, and we were walking on the coast, collecting shells. I found this one inside another small shell, and couldn't really believe I even saw it. I put it in a ziploc bag, and haven't opened it since. In fact I had forgotten about it completely until my wife found the bag in our document safe, and asked me about it. As soon as I saw my 13 year old chicken scratch on the makeshift masking tape label, the whole trip came back in vivid detail. My wife couldn't stop laughing at my proclamation on the label: "The SMALLEST Periwinkle shell in the world!!!" I actually used the caps and my exclamation points got progressively bigger. I was so sure I had a treasure when I found it. Little did I know the treasure would be the memories that would come flooding back when I found my little shell...

J