ID please

[demifelix]

I just bought some rocks today and discovered that there are some of these guys moving around. It's like a snail but with the shell the shape of a clam shell. Here's pic I took. Sorry for the quality but my cam can't do any better. It took me a whole 5 minutes to be able to get the best shot with the different setting. There are 3 guys on this rock, 1 a the bottom left with a black arrow. Does anyone know if these guys are good or should I get rid of all of them?

 

[llewella]

looks like stomatella. good guys.

 

[demifelix]

Thanks Val. I feel so relieved now. Once I can get rid of the majanos I'll be able to put the rocks in my main tank.

 

[llewella]

No problem. Good luck with the majanos. Got a blow torch?

 

[pufferchris]

+1 stomatella snail great glass cleaner