10 U.S. NATIONAL MUSEUM BULLETIN 2 27 



Prostomium suboval, with 1-7 antennae, 2 palps (latter may be rather 

 indistinctly separated from prostomium). Parapodia with subulate to 

 cirriform dorsal and ventral cirri (latter may be thickened, padlike in 

 more posterior segments). Body otherwise 24 



23. Neurosetae consisting of: (1) Limbate setae with fine tips and (2) hooded 



hooks or crotchets (figs. 67-70) Lumbrineridae (p. 256) 



Neurosetae consisting of limbate setae and with or without projecting 

 acicular setae; without hooded hooks or crotchets (figs. 71-73). 



Arabellidae (p. 268) 



24. First 2 segments apodous and achaetous 25 



First apparent segment apodous and achaetous. Prostomial antennae 7 



(5 long occipital, 2 short frontal) ; paired ventral palps short, globular. 

 Tube dwelling (figs. 64-66) Onuphidae (p. 243) 



25. Prostomium with pair of articulated antennae and pair of long curved ventral 



palps (or both short, subequal in Ophryotrocha) . Crawling or burrow- 

 ing (figs. 60, 61) Dorvilleidae (p. 230) 



Prostomium with 1-5 occipital antennae and a pair of short globular ventral 

 palps more or less fused to prostomium. Tube dwelling (figs. 62, 63). 



Eunicidae (p. 234) 



26. Neurosetae compound (some may have blades secondarily fused to shafts 



in some Syllidae) 27 



Neurosetae and notosetae simple, not compound (notosetae may be stout, 

 hooked). Tentacular segment apodous and achaetous, more or less fused 

 with prostomium, usually with 2 pairs of small tentacular cirri (fig. 30). 



Pilargiidae (p. 110) 



27. Parapodia biramous or subbiramous; notopodia at least represented by 



internal acicula 28 



Parapodia uniramous (may be biramous in sexual epitokes). Tentacular 

 segment apodous and achaetous, with 1-2 pairs of tentacular cirri. Pro- 

 stomium suboval with 3 antennae, 2 palps (latter may be reduced and 

 fused) (figs. 31-40) Syllidae (p. 112) 



28. Parapodia with varying degrees of development of extra tonguelike lobes or 



ligules (may be lacking, as in Lycastopsis) . Prostomium suboval to 

 subpyriform, with 2 frontal antennae and 2 biarticulate palps. Proboscis 

 with pair of distal dentate hooked jaws. With single apparent tentacular 

 segment with 3-4 pairs tentacular cirri. Notosetae compound (may be 



lacking, as in Lrjcastopsis) (figs. 41-45) Nereidae (p. 148) 



Parapodia without ligules (may have extra lobes, as in Nereimyra). Pro- 

 stomium suboval to subquadrangular, with 2-3 antennae, 2 palps (may 

 be biarticulate). Proboscis without jaws or jaws otherwise. With 1-4 

 achaetous tentacular segments more or less distinct, with 2-8 pairs ten- 

 tacular cirri. Notosetae simple or lacking (figs. 27-29). 



Hesionidae (p. 101) 



Superfamily Aphroditoidea 



Members of this superfamily possess paired dorsal scales or elytra 

 borne on cylindrical stumps, the elytrophores, on a certain number of 

 segments (fig. 3,a-6; in Aphroditidae, elytra may be hidden under 

 dorsal feltage consisting of modified notosetae). Prostomium dis- 

 tinct, bearing 1 to 3 dorsal antennae, a pair of elongated conical ventral 

 palps, and usually 2 pairs of eyes (0-2 pairs). First or tentacular 



