Nudi, or not a Nudi?

So i have tried and tried to get a pic that will show you guys this thing, but it always just looks like a tan blob.

What i am looking at came on a frag that i just got in today. It looks like a nudi, but it has a shell. but wait, there's more.

The shell is small relative to the size of the critter (it's only about 1/3 the length of the thing. The animal is about .5" when fully stretched) and it is flat on it's back. At first glance it looks to just be a shell resting on the animal, but with a closer look i found that it is in fact attached and is the animals shell. It is smooth to the touch anf the animal is tan with what looks like semi-textured white splotches. It also seems to have unusually long antennae (SP?) for it's size. They are as long as the critter, and they appear to be the same as your average snail's in appearance.

Now i have very limited knowledge of nudis and i am probably just plain wrong, but i have always been under the impression that they don't have any sort of shell...but this thing is not a normal snail either.
i can't find it in any of the general IDs and i have not found it during any other searches.

I need to know if it is reef safe so i don't risk my corals. I would love to keep it if i can. It's actually very interesting to watch.

So what is this thing?

 

Stomatella

 

K+!

That's it. And it looks like they are safe. Thanks for the fast response. I am glad i don't have to get rid of the little guy. He is pretty cool.

 

If you notice sometimes, you will see a white cloudy "poof" come from them. This is them mating. Shut off you filters and skimmer while they are doing that if you want more

 

That was my next question

Thanks for the help. The little guy thanks you too

 

I had some come in on liverock.. They help keep a tank clean..
Now they part of your " clean-up crew "..

Later, Larry