114 U.S. NATIONAL MUSEUM BULLETIN 227 



slightly anteriorly and gradually posteriorly. Prostomium suboval, 

 wider than long, with 3 moniliform antennae; 2 palps wider basally, 

 well separated except where their inner basal sides may be fused 

 (fig. 32a) . Tentacular and dorsal cirri distinctly moniliform through- 

 out body, tending to be alternately slightly longer and shorter (fig. 

 32, a, b). Ventral cirri digitiform, about the length of the parapodial 

 lobes. Anal cirri 3, the lateral pair long, articulate, the median 

 one a short style. Anterior end of extended proboscis with a smooth 

 chitinous rim, a single large dorsal tooth, with a ring of 10 short 

 papillae (with or without an additional ring of papillae more basally). 



Key to the New England Species of Syllis 



1. With simple setae only on all the segments (blades of compound setae par- 



tially or completely fused to shaft, with articulations obscure or absent 

 (fig. 31, g-h). Dorsal cirri with 40-70 articles. Sexual stolon (chaeto- 



syllis stage) unknown S. spongiphila (p. 114) 



With compound setae with articulations distinct, at least in anterior and 

 posterior segments. With a sexual stolon (chaetosyUis stage) .... 2 



2. Some median segments with heavy, bifurcated simple setae (blades of com- 



pound setae completely fused to shafts, fig. 32c). Dorsal cirri with 

 7-16 articles (fig. 326). Sexual stolon (chaetosyUis stage) with three 

 beaded antennae, with or without tentacular cirri (0-3 pairs, fig. 32d). 



S. gracilis (p. 116) 



All setae compound, with long and short distal blades (fig. 31, i-j). Dorsal 



cirri with 11-40 articles. Sexual stolon (chaetosyUis stage) with a single 



pair of beaded antennae, without tentacular cirri . . . S. cornuta (p. 118) 



Syllis spongiphila Verrill, 1885b 



Figure 31, g,h 

 Syllis spongiphila Verrill, 1885b, p. 435.— Hartman, 1944a, p. 339, pi. 24, fig. 10. 



Description. — Length up to 25 mm., width without setae 1.3 mm. 

 Prostomium with 2 pairs of eyes in trapezoidal arrangement, with 3 

 beaded antennae, median one longer than lateral pair. Parapodia 

 with setae few in number (2-4), simple, formed of blades which are 

 partially fused to the stem or shaft (in anterior region, fig. 3lg) to 

 completely fused (in middle and posterior regions, fig. 3lA), with tips 

 minutely bidentate or entire. Dorsal cirri long, widest basally, 

 tapering gradually, with about 50 articles (40-70). Colorless or 

 yellowish white. 



Biology. — Dredged on bottoms of mud, sand, gravel, with shells, 

 sponges, etc. It may be found curled back on itself in sponges, along 

 with Syllis cornuta and Eunice norvegica. 



Material examined. — Numerous specimens from off Massachu- 

 setts to off Chesapeake Bay, 81 to 317 fathoms. 



Distribution. — Off Massachusetts to off Chesapeake Bay. In 70 

 to 317 fathoms. 



