Alison Young called this...
Not the best pics, but a cool worm. Under a rock high in the intertidal, outer coast. In a mucus tube in sand. Had internal feedings bits it could exsert, but I didn't see any jaws. ~ 12 cm long.
C. Piotrowski, C. Dixon, S. Ellsworth, N. West, M.E. Hannibal
A fisherman was slurping these "pile worms" out of the sand with a PBC suction deal along with the ghost shrimp to use for bait. He claims if you try to pick them up these crazy jaws come out and bite you!
The genus Glycera is a group of polychaetes (bristle worms) commonly known as blood worms. They are typically found on the bottom of shallow marine waters, and some species (e.g. the common blood worm, Glycera dibranchiata), are extensively harvested along the Northeastern coast of the United States for use as bait in fishing. Another common species is the tufted gilled bloodworm, G. americana.