Snail?

[maddux]

I have seen this thing on the glass at the back of my tank before, it looks like a snail without the shell (it does have a small dark shell of some kind but doesn't come close to covering it.) It has two whiskers on the front. When I took this picture it was blowing something green out at the zenia. I have no idea what it is. Any assistance would be appreciated.

 

Thanks.

[just dave]

Stomatella sp.