Ringed

A mystery close-up  — Can you guess what animal it is?

 

Here's a view from the side:

 

And one of the entire shell:

 

Purple-ringed Top Snail, or Jeweled Top Snail (Calliostoma annulatum)

Photographed on 16 February 2016.  Note that "annulatum" comes from "annulus" or "ring".