When I was a little girl, I used to think shells like this were magical and that if you wished on the shimmery reflections of the sunlight on the water (glints) your wish would come true. I read so in a book and took it to heart. Seal Child was the name of the book...I'm sure you could find it on Amazon if you're so inclined.
I also used to hold my ankles together with diving rings to force me to swim like a mermaid under water. Lacking gills, I could never remain submerged as long as I hoped, but enjoyed the fantasy nonetheless.
Back when I was brown as a blueberry (something my mom would say that I still can't make heads or tails of) and full of imagination. Now, I'm pasty and pragmatic.