Margarita Snail - Unidentified sp. Picture taken June 2000.
Nikon Coolpix 950 digital camera, Tiffen +10 Closeup Lens, no flash

This is closeup of a Maragrita snail which is a very good diatom algae eater and it does a very good job at reducing short turfs of hair algae on rocks. I find however that this snail doesn't stay on the rocks and stays mainly on the glass.

These snails stay fairly small, the snail pictured is about the size of a U.S. Nickle coin, and I've never seen one get as big as a U.S. Quarter coin.