POLYCHAETE WORMS, PART 1 253 



first, gradually getting larger. They will regenerate lost parts in a 

 relatively short time. 



When incorporating foreign material in the tube (Linville, 1903), 

 the tentacular cirri and ventral palps are used as feelers. Objects to 

 be incorporated in the tube are picked up or pushed by the strong 

 ventral palps or by the mandibles, the body contracts and the object 

 is placed on the edge of the tube. The worm glues the object to the 

 tube securely by pushing outward, rubbing the ventral mucous glands 

 against the inner surface of the tube. According to Linville, while in 

 the tube, the worm moves the body up and down regularly at the rate 

 of 44 tmies per minute; this creates currents of water passing in and 

 out of the tube for aeration. Other respiratory movements include an 

 alternate movement of the branchiae outwardly and inwardly, an 

 alternate spiral constriction and reverse spiral extension of the entire 

 branchia, and the waving of the minute branchial filaments toward 

 and away from the central stem. The adults are hardy and their 

 tube-building habits can be observed readily. They are carnivorous. 

 They can be kept alive in the laboratory by feeding them Mytilus 

 (Allen, 1959). 



According to Andrews (1891b), in North Carolina the young were 

 found in the tow net in July. According to Monro (1924) in Panama, 

 developing eggs and larvae were found in the tubes of the adult, the 

 eggs evidently being laid in the tube where the larvae developed. 

 The early development has been followed to some extent by Andrews 

 (1891b, Beaufort, North Carolina), Monro (1924, Madeira, Panama), 

 and Allen (1951, 1953, and 1959, Woods Hole region, Massachusetts). 

 Allen found that the eggs were mature and could be artificial!}^ ferti- 

 lized in June through August (more successful in June and July than 

 in August) ; a rather low percentage of activation was the general rule. 

 The eggs were up to 240ju in diameter, very opaque, creamy j^ellow to 

 greenish; during maturation, the eggs had algal-like strings of nurse 

 cells attached. 



After fertilization, development took place with amazing rapidity. 

 At 3 hours, there were ciliated larvae, at 24 hours rotating trocho- 

 phores. They developed into surface swimmers for a relatively short 

 time, the larvae of 4 days tending to crawl on the bottom, secreting 

 mucus and forming transparent slime tubes (larvae with four setigers 

 and moveable jaws). At 5 days, they had settled on the bottom, in 

 transparent slime tubes and appeared to be feeding (larvae with 4-5 

 setigers, 5 occipital antennae, 2 anal cirri, 4 types of setae); at 13 to 

 17 days, the larvae had seven setigers, with jaws working actively. 



Allen (1952) found D. cuprea to be parasitized by a species of 

 arabellid; 63 specimens of tlie parasite were recovered from a single 



