326 PROCEEDINGS OF THE ACADEMY OF [JlUie, 



deep cleft, from which the setse arise and into which the tips of the 

 aciciila enter. Neurocirri arise obhqiiely from basal half of neuropo- 

 dium, cylindrical or slightly tapered to blunt tips reaching well beyond 

 end of neuropodium, especially on anterior segments. Notocirri 

 arise from rather prominent but indistinct cirrophores immediately 

 above base of neuropodia and all at same level. Styles all approxi- 

 mately of one length, about tw^o-thirds width of body, the anterior 

 and alternate ones scarcely longer than the others, but the alternate 

 ones carried erect. Anterior notocirri are somewhat articulated, 

 similarly to the tentacles, but this character becomes more obscure 

 toward the base and on more caudal cirri; most of them are rather 

 stout, rather quickly tapered and more or less transversely wrinkled, 

 rather than jointed. Near the caudal end they become much reduced 

 in size. 



Acicula number from five or six anteriorly to two or three posteriorly ; 

 pale yellow, tapered, the ends blunt and very slightly knobbed (PI 

 XV, fig. 6). 



Setse generally about twelve or fifteen, in oblique, spreading, fan- 

 shaped tufts; colorless, the stems long, slender, curved, the ends 

 (PI. XV, fig. 7) slightly enlarged, oblique, wdth four or five just per- 

 ceptible teeth on the convexity of the front face and a slight shoulder 

 behind. Appendages moderately long, varying from three times 

 diameter of distal end of stem in ventral to five times its diameter 

 in dorsal setae, except at the posterior end, where all are shorter. 

 They (fig. 7) are of peculiar form with very oblique base, beyond which 

 the width remains nearlj^ uniform; distally abruptly truncated and 

 ending in a stout oblique spur, above which is a delicate curved tooth 

 often nearly worn away; a very fine marginal fringe ending in a more 

 prominent tuft of hairs. 



This species stands closer to the type species than any of the three 

 already described from the Pacific coast of North America. Johnson's 

 species, P. elongata, appears to be more properly referred to SynsylUs 

 Verrill. Much confusion in the usage of the genus exists among authors . 

 Station 4,430, off Santa Cruz Island, April 14, 197 fathoms, black 

 sand and pebbles. Two specimens. 

 Pionosyllis gigantea Moore. 



About forty anterior segments of a specimen of this large species 

 from an unknown locality. As noted above it is doubtful if this species 

 really belongs to Pionosyllis. 

 Trypanosyllis intermedia Moore. 



Owing to the deficiencies of the type the original description of this 

 species is incomplete and may be added to here. 



