shell of marine snail

Question
Dear Mr Rhudy!

In your expertise you specify, that you are an expert on snails, too. But I do not know, if you can answer my question:

On this photo in the link is a hermit crab in a shell. Can you identify the snail, what belongs to this shell?

Here is the link:
http://foto.arcor-online.net/palb/alben/17/2259617/6137353661626666.jpg

Thank you for your effort with this difficult question, Xaver...

Answer
I'm afraid that I don't know much about marine species.  The crab and shell are from the ocean.  I'm familiar with freshwater species of snail to some extent but know less about marine snails.  I'm afraid I can't answer your question.  Sorry.

Ms. Rhudy