92 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 7 



a slender papilla. Third segment with a long, slender, cirriform dorsal 

 cirrus and a globular ventral cirrus. From the fourth segment pos- 

 teriorly, both dorsal and ventral cirri are globular. Parapodia subbi- 

 ramous, the notopodium represented by an embedded aciculum, the 

 neuropodium well developed, provided with an aciculum, 1 or 2 simple, 

 blunt, acicular setae, and several composite setae. These setae consist 

 of a shaft with a longitudinal series of spinelets in 2 rows, disposed 

 along the outer, ectal edge of the shaft, and an appendage with a slender 

 falcate piece, with a row of delicate spinelets along the cutting edge. 



Pisionella hancocki, new species 

 Plate 27, Fig. 326; Plate 28, Figs. 327-333 



Collections. — 366-35 (Holotype), 375-35. About 14 specimens. 



Long, slender, depressed cylindrical, tapering gradually in both di- 

 rections from near middle of body. Number of segments 120 or more; 

 length of a smaller, 120 mm individual is 35 mm, of a larger, incom- 

 plete individual of 80 segments is 28 mm. Greatest width, at about the 

 fiftieth segment, is 1.04 mm without, 2.07 mm with parapodia. The pro- 

 boscis is visible dorsally through the body wall as a dark streak extend- 

 ing through the first fourteen segments. 



Prostomium slightly elevated, produced between the first few seg- 

 ments, extending posteriorly to the fourth segment (third setigerous) ; 

 provided at its anterior margin with a median cirriform antenna, that 

 is about half as large as the dorsalmost cirrus of the first segment. Two 

 pairs of deep-seated eye spots, of which one or both pairs are more or 

 less fused, are present near the middle of the prostomium (pi. 27, fig. 

 326). The proboscis (dissected) is lined with dark pigment. It has 2 

 dorsal and 2 ventral stout jaws (pi. 28, fig. 329), and 19 or 20(?) 

 soft, terminal papillae. Their exact number could not be ascertained 

 after dissection. 



First segment greatly modified, enlarged, extending forward at the 

 sides of the prostomium so that its inner, proximal base is in contact 

 with the base of the prostomial antenna. At its terminal end it is pro- 

 vided with 3 tentacular cirri, the dorsalmost about twice as large as 

 the prostomial antenna, the median one about as large as the prostomial 

 antenna, and a long, stout ventral cirrus (pi. 27, fig. 326) about as 

 long as the first 6 normal segments. No setae or acicula have been made 

 out in this segment. 



