Nautilus.

Since a couple of you got close to identifying the image I posted yesterday, I decided to put another one up today - along with a name! I picked the shell up on a trip to Capri and carried it carefully home in my hand luggage on the plane (like that's ever gonna happen again!). Despite the damage that was done recently it is still one of the most amazing things I have ever seen. I am guessing, but I think the "furry" bits that everybody saw can be attributed to the dark coloration on the outside of the mouth of the shell. Thanks for all the lovely comments.