POLYCH^TA 289 



Family C. NEPHTHYDIDAE. 



Elotij^ated polycluets with flattened dorsal and ventral surfaces, 

 giving a quadrangular cross section; prostomium with 4 small tentacles, 

 the ventral pair being modified palps; peristomium with parapodia bear- 

 ing setae and a pair of short cirri; proboscis veiy large with long fleshy 

 projections in front; the two lobes of the parapodia widely separate: 

 few genera and species. 



Nephthys Cuvier (Fig. 452, C). Characters as given above: nu- 

 merous species, 4 in the Woods Hole region. 



N. incisa Malmgren (A^. ingcns Stimpson). Proboscis with large 

 dorsal and small ventral papillae; length 13 cm.; color white: Long 

 Island Sound to Bay of Fundy and northwards, from below low-water 

 mark to 60 fathoms, on muddy bottoms; Europe; common. 



N. bucera Ehlers {N. picta EhL). Body slender with over 100 seg- 

 ments ; setae very long, often exceeding in length the diameter of the 

 body; forward tentacles longer than half the width of head; length 20 

 cm. ; width 5 mm. : South Carolina to Massachusetts Bay, in shallow 

 water in sand, and among rocks. 



Family 7. LEODICIDAE. 



Elongated polychiets with a complicated jaw apparatus in the pro- 

 boscis; the cirri of the anterior parapodia form branching gills in most 

 species; prostomium either with 3 to 5 tentacles and a pair of palps or 

 without cephalic appendages; usually a permanent parchment-like tube 

 formed: about 30 genera with several hundred species. 



Key to the genera of Leodicidae here described : 



Oi Gills present, 

 fci Peristomium consisting of 1 segment and with cirri ; gills branched. 



2. DiOPATRA 



62 Peristomium consisting of 2 segments. 



r?i Gills branched 1. Leodice 



C2 Gills simple 3. Marphysa 



ttn Gills absent. 



hi Head without appendages. 



Ci Eyes absent -. 4. Lumbrineeeis 



C2 Four eyes in a transverse row 5. Arabella 



62 Head with appendages <;. Stauronereis 



1. Leodice Savigny {Eunice Cuvier) (Fig. 452, D). Body elongate 

 with numerous segments; peristomium consists of 2 segments with 1 pair 

 of cirri; 5 tentacles and 2 large palps present; gills begin usually on sixth 

 segment: species very numerous, 2 in the "Woods Hole region, in rather 

 deep water. To this genus belong the largest known polvch^^ts, the larg- 

 est species having a length of 1 m. and more. 



