Identify Odd Creature

Hi all, I can't really get a picture of this, so hopefully my description will do it justice! I noticed about a dozen or so extremely fine, hairlike strands or 'tentacles' coming out from one point under a piece of rock. I thought at first it was some type of algae until I noticed that the strands were feeling around the sand, and that they would slowly retract if disturbed. The strands seem to be probing around for food as best as I can tell, and I'd say they are at least 2"-3" long, at least what I can see of them. It's never moved, always from the same point under the rock. Does this sound familiar to anyone, and if so, is it something good or bad? Thanks!

 

Im guessing spaghetti worm. Google it and you will see what they look like.

Marc.

 

Thanks Marc! Google'd it and found a picture, sure enough that's it. Now I can rest easy