This can easily be my favorite shell, mostly for that beautiful colorful necre layer inside. We call it St Peter's Ear, and I believe eng name is Ormer (one type of ormer).
And this photo may easily qualify for text book photo, for it's boring background. I am not happy with background, but I am happy with a shell, because I wanted to present the whole thing, at least the inside...
This shell is a great example of golden ratio in nature...
