172 U.S. NATIONAL MUSEUM BULLETIN 227 



water soaked wood. On rocky shores, it is found under rocks, stones, 

 in the sand among mussel beds. It is found among the roots of de- 

 ca3nng marsh grass and eelgrass. It is rarely found in scrapings 

 from floats, pile scrapings among tunicates, sponges, barnacles, etc. 

 It was found at only 2 stations in connection with the oceano- 

 graphic fouling studies in the New England region. 



It burrows at depths of from 7 to 45 cm., the largest specimens 

 usually found at the greatest depths. It secretes a viscid fluid which 

 binds the grains of sand together, forming a loose and flexible, irreg- 

 ular burrow. The abundant mucuslike secretion gives smoothness 

 and some coherency to the walls of the burrow, but it does not form a 

 solid tube. It feeds with the anterior end protruding out of the 

 burrow, crawling to the food, seizing it with its powerful jaws and 

 jerking it down into its burrow. It may show circular searching 

 movements of the anterior end, when it is stimulated by food juices. 



It comes out at times from the burrow, especially at night, to forage 

 on the surface and swims about at the surface of the water. It is very 

 active, swift, voracious and predatory, feeding on other worms and 

 various kinds of marine animals; it also feeds on algae (Ulva). It has 

 a keen sense of food detection (Copeland and Wieman, 1924) and will 

 respond to most minute particles of ground clam meats. Chemical 

 sense is the primary one upon which its responses to animal food de- 

 pend, sight playing little part in the worms' food reactions. It can 

 be induced to enter glass tubes of appropriate diameter, placed in sea 

 water; the tubes are soon lined with mucus; it will behave essentially 

 as it does in its natural burrows in the sand. There is a rhythmic 

 undulatory movement of a variable portion of the body, taking 

 place in a dorsoventral direction, these muscular waves produc- 

 ing a current of water passing along the body from the anterior to 

 the posterior end. The current of water in the burrow would bring in 

 a constant supply of fresh water as well as be a factor in conveying 

 food stimuli to the sense organs. 



It is capable of considerable migration. The worms have been ob- 

 served moving along drainage channels with the incoming tide, along 

 the surface of the flats for as much as 12 feet before reburrowing in the 

 flats (Dow and Wallace, 1955). Young worms, up to 60-65 segments, 

 were gathered at night, swimming at the surface (Eel Pond, Woods 

 Hole, Massachusetts, June 27, 1954). 



The worms are dug out by the tautog, scup, and other fish and, being- 

 one of the largest and most abundant of polychaetes in the New 

 England region, form an important item of food for many fish. They 

 are used extensively as bait by line fishermen. Along with the blood 

 worms, Glycera, they are of commercial importance for the United 

 States salt-water sport fishery which extends from Connecticut to 



