I was convinced these were "scotch bonnet" shells until I learned yesterday from my favorite shelling blog (and subsequent research) that scotch bonnets are a very rare find. So either A) Statia is a previously unknown breeding ground for them, B) I'm just really really lucky, or C) More likely, they're not scotch bonnets at all. In any event, they're pretty to look at.
My two favorites. I know the one on the right is really worn down, but I love love love the calico coloring.