Greyish ball (sponge?) on rock - anyone know?

[cju84]

Hey all - I set up a tank about a week ago and there is a greyish object (almost looks like some sort of snail shell) on my rock. I checked the sticky but wasn't sure what it is (maybe a sponge or some sort?).

 

The object seems smooth and has not moved (I don't think it is a snail).

 

Any idea/thoughts would be great. Thanks!

[hey]

looks like a sea squirt I think I see sonme veiny looking stuff on it.