ID query - strange worm

[docklink]

I appologize for not having a photo for this, if I manage to get one, Ill post it. Twice now, I've seen a worm crawling through and over the substrate. At first glance, it looked like the arm of one of the reticulated brittle stars, about as thick as one of the smaller ones with similar gray color with black (or very dark gray) banding but the bloody thing is 4 to 5 inches long .... it just keeps going and going!! Its head appeared blunt without any antenna or appendages and there are no bristles or protuberences of any kind. Anyone have a clue or see something similar in their setup? I've been inable to locate an ID with my searches so far.

 

[skippy2]

peanut worm or ribbon worm

 

[docklink]

Photos finally

Photos finally

Got a couple of (lousy) photos of this beastie. It's not a peanut worm by any stretch. Not sure about a ribbon worm, but possibly. The photos are of about the front 1/5 of the worm. Overall length looked to vary from about 6 to 10 inches. About the thickness of a pencil lead but able to stretch much thinner.