POLYCHAETE WORMS, PART 1 169 



1900). They have been observed swimming in incredible nmnbers in 

 Long Island Sound in August (Verrill and Smith, 1874), when they were 

 eagerly pursued by the bluefish. They have been observed breeding 

 in September in Beaufort, North Carolina (Wilson, 1900; Andrews, 

 1891a). They appeared in large swarms swimming in the Cooper 

 River, South Carolina, opposite the Navy Yard, April 23, 1925 

 (reported by Commander A. K. Atkins, specimens in USNM). 



The swarming behavior has been followed by Lillie and Just (1913) 

 and others in the Woods Hole area. They were taken after sunset on 

 certain nights, in general, during the "dark of the moon" during June 

 to September. They appear swunming near the surface of the water 

 very soon after sunset and ma}^ be attracted by a light. The swarming 

 usually begins with the appearance of a few males, distinguished by 

 their bright red anterior segments and white sexual posterior segments, 

 darting rapidly tlu-ough the water in curved paths. The much larger 

 females, paler in color, often nearly white, then begin to appear, 

 usually in smaller numbers, swimming slowly through the water. 

 They increase in number for a time, then decrease and finall}^ disappear 

 after a couple of hours. The female is surrounded by several males, 

 which swim rapidly in narrow circles about her. The males begin to 

 shed sperm and soon the female begins to shed her eggs, then slowly 

 sinks into the water to die. Some kind of emanation from the mature 

 egg-filled females incites the males to shed sperm. For the female, 

 the presence of sperm in the sea water incites the shedding of eggs. 



The early development has been followed by Banse (1954, in Kiel 

 Bay in western Baltic); the adults swarm in July; tlie eggs are about 

 140jLi in diameter; they develop rapidly into planktotrophic larvae 

 and change to bottom forms when they have 4-6 segments, playing 

 no further role in the plankton; occasionally they may remain in the 

 plankton until they are 1.4 mm. long. 



Material examined. — Numerous specimens from Gulf of St. 

 Lawrence (Prince Edward Island), Nova Scotia (Cape Breton Island), 

 Newfoundland, Maine (Days Cove, Damariscotta River), New 

 Hampshire (mouth of Squamscott River, Great Bay, mouth and 

 middle of Oyster River, Belamy River), Massachusetts (Buzzards 

 Bay; New Bedford; North and South Ponds, Megansett Estuary; 

 Elizabeth Islands; Cape Cod, Sandwich, Wellfleet, Follins Pond, head 

 of Bass River, West Yarmouth, Cotuit; Martha's Vineyard, Lagoon 

 Pond, Senekontacket Pond), Connecticut (New Haven), Rhode 

 Island, New Jersey (Long Island Sound), Delaware (Assonoman Ba}^), 

 Maryland (Chesapeake and Chincoteague Bays; Ocean City), Virginia 

 (Cape Charles, Norfolk), North Carolina (Beaufort), South Carolina 

 (Cooper River, opposite the Navy Yard), Florida (Apalachicola Bay), 



