Yeah dude, its eaten 4 now. I cant imagine they 'go' anywhere. I passed off all the others as my imagination gone wild. But there is no doubt this is a ceirth snail. My acans are getting in on the action too.
Yep, coral will eat snails. I guess they suck the flesh out and toss the shell back. It's happened to me on several occasions as well. I'll see if I can find some pics.