The solution to Bit-o-Critter round 18

Nobody guessed at BoC round 18 on the blog, although one colleague got it right on Friend Feed.  It was the eye and proboscis of a stromb, which is a big family of marine gastropod snails.  They are related to cone snails, but can always be distinguished by a ntoch on the margin of their shell that allows them to poke out the eyes and look around.  They have very engaging, almost comical eyes, but they probably don't see the world as we do.  The particular one I chose was a spider shell, which you often see for sale in tourist shops (and shouldn't buy, naturally)