Help with ID

[pascal32]

I found one of these snails the other day. I set it to the side in the tank to take a picture and now hes gone.

any more insight on what this is?

http://www.zoaid.com/index.php?module=Gallery2&g2_itemId=1733

 

[Dave VG]

Sundial snail remove it ASAP if you can. They eat zoas.

 

[tmz]

Heliacus sp, an architectonicid snail ,commonly called a sundial . Usually about half the size of a dime or smaller. Deadly to zoanthus. You may be able to see it in a bed of zoanthus when the polyps are retracted