POLYCH^TA 



297 



FAMILY 4. AMPHICTENIDAE. 



Small worms which form tubes of sand open at both ends which 

 can be carried about by their occupants; the prostomium bears short 

 filamentous tentacles which are protected by long yellow setae; hinder 

 end of the worm without parapodia and folded on the forward part: 

 several genera and few species. 



PEOTINARIA Malmgren. Characters as given above: several species, 

 2 in the Woods Hole region. 



P. gouldi (Verrill) (Fig. 470). Body flesh-color, mot- 

 tled ; length 4 cm. ; width 7 mm. : North Carolina to Maine ; 

 in shallow water. 



SUBORDER 4. CAPITELLIFORMIA. 



Head pointed and not distinctly set off, 

 without tentacles or palps but with a pair of 

 ciliated, retractile, tentacle-like organs; para- 

 podia rudimentary, with sessile capilliform 

 setae on the anterior and sessile hook-like 

 ones on the posterior segments; proboscis 

 without jaws : 1 family. 



FAMILY CAPITELLIDAE. 



With the characters of the suborder: 

 several genera. 



1. NOTOMASTUS Sars. Prostomium con- 

 ical, without eyes; body composed of 2 por- 

 tions, a forward thicker part (thorax) consisting of about 12 biannu- 

 lated segments, and a long hinder portion: several species, 3 in Woods 

 Hole region. 



N. luridus Verrill. Long, cylindrical worms, 15 cm. long, 2 mm. 

 thick; color dark brown: Long Island Sound to Maine; at low-water 

 mark in tubes in muddy sand. 



N. nliformis Verr. Body filiform, 10 cm. long, 1 mm. thick; color 

 pale red, often mottled with whitish : Long Island and Vineyard Sounds ; 

 at low-water mark. 



2. CAPITELLA Blainville. Large genital setae on 8th and 9th seg- 

 ments; thorax consisting of 9 segments; only the middle portion of the 

 body with setae: several species, 1 in Woods Hole region. 



C. gracilis (Verrill). Length 5 cm.; color red; head trian- 

 gular: Cape Cod to Bay of Fundy; in tubes in the mud in shallow 

 water. 



Fig. 470 Pectinaria gouldi 

 (Verrill). A, the worm ; B, its 

 tube. 



