Need help in identifying!

[steelfirez]

I recently went on a trip to mexico. I found an interesting shell and decided to bring it back. It's about 3" long, with bumps on ridges going all the way around. Most of the bumps are eroded, showing a pearly sheen inside. There is a pearly sheen when looking inside the shell, and it's white where there isn't this grassy type thing covering it(probably some kind of algae). The grassy type thing is dry. Anyone can help me identify it?
Note: will post picture soon  <span class="petit">--Last edited by steelfirez on 2010-02-17 21:09:41 --</span>

[dave r]

Sounds like an Abalone shell but we need a picture really.
Dave