120 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.10 



setal fascicle is still full but less so than in the seventh, and it comes to be 

 decreasingly so farther back. A fifth parapodium has about 25 to 30 

 superior simple setae and about the same number of inferior hooks; a 

 seventeenth parapodium has about one third again as many setae, but 

 shortly thereafter there is a decrease, so that by the sixtieth parapodium 

 there are only 20 simple setae, 6 or 7 composite hooks, and 7 or 8 pecti- 

 nate setae, together with 2 subacicular hooks. A tenth last parapodium 

 has even fewer setae and hooks and lacks the subacicular hooks. 



The notoacicular fascicle is represented by a slender group of fine 

 rods, completely embedded. The superior simple setae are practically 

 without wings, resemble capillaries. The inferior composite setae resem- 

 ble spinigers, but under very high magnification the tip is seen to be 

 weakly bidentate (pi. 8, fig. 171) or even tridentate (pi. 8, fig. 172) be- 

 neath the long, tapering, hooded cap. The inferiormost have an append- 

 age about as long as the superiormost, but a gradual decrease in length of 

 appendage is attained in going from anterior to posterior regions (pi. 8, 

 figs. 170-173). Also, the bidentate nature of these setae is more obvious 

 in median and posterior parapodia, where the true nature of the biden- 

 tate tip is more clearly marked. Pectinate setae are present in median and 

 posterior parapodia; about 8 of them are in the seventeenth setiger. They 

 are fine, slenderer than the other setae, have a distally flaring end, which 

 is, however, rolled in at the sides, causing it to appear narrower than it 

 actually is (pi. 8, fig. 189). There are about 10 long dentations at the 

 edge. 



Subacicular hooks are first present from the twenty-fifth setiger, occur 

 at first singly in parapodia, replacing some of the composite hooks at the 

 lower end of the fascicle. They are clear yellow, distally tridentate, 

 hooded (pi. 8, fig. 166). They are present through most of the body 

 length, but seem to be absent from at least the last 15 parapodia. They 

 are somewhat slenderer than the acicula with which they occur ; there are 

 often 3 or 4 in vertical series in a single parapodium. Acicula are yellow, 

 typically 2 in a parapodium; they taper distally to a slightly bent tip 

 (pi. 8, fig. 169). 



The proboscidial armature is translucent, in part, but heavily tinged 

 with black, especially in the thicker regions. The free ends of the mandi- 

 bles, when not eroded, are shining white, appear winglike (pi. 8, fig. 

 164) ; when worn, the calcareous parts may be more or less missing (pi. 

 8, fig. 165). The mandibles are widely separated from one another at the 

 base, but well fused in their distal half (pi. 8, fig. 165). The maxillary 

 carriers are longer than broad, basally rounded (pi. 8, fig. 167). Forceps 



