322 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 



PLATE 48 



Figures 38, 39, Polydora armata: Fig. 38, a hooded hook from a poste- 

 rior segment, x 650; Fig. 39, two modified spines from fifth 

 setiger, x 370. 



Figure 40, Polydora ciliata, modified spine and its companion pen- 

 noned seta from fifth setiger, x 370. 



Figures 41, 42, Polydora socialts: Fig. 41, modified spine from fifth 

 setiger, x 290 ; Fig. 42, hooded seta from seventh setiger, x 290. 



Figure 43, Polydora giardi, series of 5 modified hooks from one side 

 of fifth setiger, showing gradation of changes in accessory tooth, 

 X 370. 



Figures 44, 45, ?Boccardia redeki: Fig. 44, modified hook with com- 

 panion pennoned seta from fifth setiger, x 290 ; Fig. 45, hooded 

 hook from a posterior segment, x 290. 



Figure 46, Polydora uncata, a modified spine from a posterior para- 

 podium, X 65. 



Figures 47 to 49, Polydora ligni: Fig. 47, a 19-segmented larva from 

 plankton, showing characteristic paired pigment pattern on ante- 

 rior segments, x 53; Fig. 48, a modified spine from fifth segment 

 from same individual, x 370; Fig. 49, a 3-segmented planktonic 

 larva, believed to be this species, x 260. 



Figures 50 to 53, Spionid larva: Fig. 50, chaetosphaere position after 

 fixation, x 85; Fig. 51, a young planktonic larva with prickly 

 pygidium, in life, x 85 ; Fig. 52, another similar larva with setae 

 partly thrust laterally, x 85 ; Fig. 53, a pair of hooded hooks from 

 ninth segment of preceding, showing bifid distal end, x 650. 



