POLYCHAETE WORMS, PART 1 127 



Key to the New England Species of Streptosyllis 



1. Parapodia with enlarged acicula in setigers 2 to 20 or 23. At least basal part 

 of palps visible dorsally; distal conical part may be turned ventrally. 



S. \arians 



Parapodia with enlarged acicula in setigers 2 to 5. Palps ventral, not visible 



dorsally S. arcnae 



Streptosyllis varians Webster and Benedict, 1U87 



Figure 31^ 



Streptosyllis varians Webster and Benedict, 1S87, p. 718, pi. 2, figs. 24-31, pi. 3, 

 figs. 32-34.— Not Fauvel, 1923, p. 281. 



Description. — Length up to 8 mm., width up to 0.8 mm., segments 

 up to 50. Upper simple seta curved, serrate near tip (not winged). 

 Stem of compound setae with 2-3 terminal prongs; terminal blade of 

 anterior parapodia very short; more posterior parapodia with blades 

 somewhat longer, truncate, may have bifid tips, without covering 

 membrane (as in S. arenae). Colorless. When mature, modified as 

 sexual epitokes, with capillary swimming setae beginning on setiger 

 21; males with white sperm massed in bod}^; females with few large 

 pol3"gonal white eggs. 



Biology. — Found at low water, in coarse sand and gravel. 



Material examined. — Rustico Harbor, Prince Edward Island, 

 type specimens from Eastport, Maine. 



Distribution. — Gulf of St. Lawi-ence to Maine (Eastport). In 

 low water. 



Streptosyllis arenae Webster and Benedict, 1884 



Figure 3l,l,m 



Streptosyllis arenae Webster and Benedict, 1884, p. 711, pi. 2, figs. 17-21, pi. 3, 

 figs. 22-23.— Miner, 1950, p. 298, pi. 98. 



Description.— Length up to 8 mm., width up to 0.5 mm., segments 

 up to 55. Upper simple setae straight or slightly curved, bluntly 

 rounded, with tips winged (covered by a membrane). Stem of com- 

 pound setae with 4 terminal prongs; terminal blades of anterior 

 parapodia very short; more posterior parapodia with blades short to 

 longer, with tips covered by a membrane. Colorless or brownish 

 yellow. Sexual epitokes unknown. 



Biology. — Found at low water, in sand. 



Material examined. — Type specimen from Province town, Massa- 

 chusetts. 



Distribution. — Massachusetts (Cape Cod). In low water. 



