BAD snails on Coral?

[mrg02d]

Hello,
I just got some coral polyps yesterday. Im not sure what they are called, but I think they are nick named "zoos". They are soft coral polyps on a rock. Three small snails hitchhiked into the tank via the rock. Today I noticed one spending too much time on the coral and I picked him off and put him in a glass. It looks like he damaged the coral!

They are about .5 inches long and have a siphon like the nessarius snails do. I havent seen any of the other snails stay too long on the corals, nor cause any damage. (Cerinths love to hang out around them, but never seem to hurt them aside from bother the polyps into closing)
I took a picture. What is this? I managed to get two of the three out. I dont know where the third is. Maybe a hermit crab will get him...

Thanks,
Matt

 

[roka64]

Shells aren't always the easiest way to ID snails. Can you get a pic of it on the glass or the bottom of it?

 

[juice28]

it is a safe call to remove them if you are unsure, you can always and easily replace a snail...