Recognize this purple worm?

[unbelizeable]

This is also linked in my opening thread (in general), but I'm posting the pic here to see if anyone knows what it is.
The picture was taken in 90 feet of water in shale beds just north of the Monterey Harbor jetty (CA). The whole animal was probably a little over two feet long. Can't find a reference to it in the invertebrate books. A clearer picture is at: 08.12.21.anchorFarm.0039 on Flickr - Photo Sharing!