POLYNOIDAE. 37 



5. Drieschia pelagica Michaelsen, Jahrb. Hamb. wiss. anstal., 1892, 9, 

 p. 6, fig. 15-18. Off Ceylon. 



6. Plotolepis nans, gen. et. sp. nov. Pacific near Easter Island. 



7. Plotolepis pellucida (Moore), Proc. Acad. sci. Phil., 1903, p. 794, pi. 50, 

 fig. 1-12. From the Atlantic off Massachusetts. 



8. Podarmus ploa, gen. et sp. nov. Pacific off Easter Island. 



9. Quetiera pelagica Viguier, Ann. sci. nat., 1911, ser. 9, 13, p. 252; 1912, 

 ser. 9, 15, p. 89, pi. 2, 3, f. 1-6. Mediterranean. 



10. Frenna dubia Viguier, op. cit., 1912, ser. 9, 15, p. 94, pi. 2, 3, f. 11. 

 Mediterranean. 



Ehlers thinks it possible that his Herdmanella gracilis from off the African 

 coast is a pelagic form; but this is uncertain as it was among forms secured at 

 depths from 1,500 to 2,000 meters in the vertical net. (Deutsch. tiefsee-exped. 

 Valdivia, 1908, 16, p. 44, pi. 5, f. 1-4). 



Key to Genera. 



a. With only two tentacles. 



h. With a facial tubercle; notopodial setae finer than the neuropodials. 



c. Eyes present; elytra with surface in part papillose Iphione Kinberg. 



cc. No eyes; elytra smooth Iphionella Mcintosh. 



bb. No facial tubercle; notopodial setae coarser than the neuropodials Bylgides, nom. nov. 



aa. With three tentacles. 



b. Lateral antennae inserted at margin of prostomium. 

 c. Pelagic forms; these comparatively short, colorless and transparent; setae ordinarily con- 

 spicuously elongate or of a special natatory type. 

 d. Parapodia strictly uniramous, the notopodium represented by neither lobe, aciculum or setae. 

 e. Notocirri unequally developed, those of the anterior region and alternate ones in the 

 posterior region decidedly elongate and more or less inflated. . . .Plotolepis, gen. nov. 

 ee. Notocirri not thus very unequally developed. 

 /. Setae of one type, fine, capillary, and long. 



g. Neurocirri attached near the middle of neuropodium or proximad of it, the first 

 elongate but all others very small, falling clearly short of attaining the distal end. 



Quetieria Viguier. 

 gg. Neurocirrus attached far distad of middle of neuropodium, the distal end of which it 



much surpasses Frenna Viguier. 



//. Setae of two forms, one long and fine and the other shorter and stouter, all with tips 

 entire. 

 g. Parapodia all with a conspicuous, though short, cylindrical or somewhat clavate 

 process from posterior surface just above insertion of neurocirrus; coarser ventral 

 setae straight, nearly as long as the dorsals and equally as numerous. 



Podarmus, gen. nov. 



gg. Parapodia with no such process from the caudal side; coarser ventral setae much 



fewer and very much shorter than the finer dorsals, and more or less sigmoidally 



curved Drieschia Michaelsen. 



dd. Parapodia biramous. 



e. With a median process or " subtentacular cirrus" beneath the median tentacle; no noto- 

 podial setae; pairs of elytra eighteen Harmopsides, gen. nov. 



ee. With no subtentacular cirrus; in each notopodium a stout seta in addition to the aciculum; 

 pairs of elytra eleven Nedochaela Marenzeller. 



