POLYCH^TA 289 



FAMILY 6. NEPHTHYDIDAE. 



Elongated polychaets 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 very 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 (N. ingens 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 polycheets 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 : 



a x Gills present. 

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



2. DIOPATBA 

 6 2 Peristomium consisting of 2 segments. 



c t Gills branched 1. LEODICE 



c 2 Gills simple 3. MAEPHYSA 



rt. Gills absent. 

 6 X Head without appendages. 



c t Eyes absent 4. LUMBRINEREIS 



c 2 Four eyes in a transverse row 5. ARABELLA 



6, Head with appendages 6. 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. 



