436 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 10 



The first setigerous segment is complete with notopodia and neuro- 

 podia; a retracted lateral organ is visible between the 2 rami, in a depres- 

 sion and slightly nearer the notopodium. Farther back the parapodial 

 fascicles increase in size and come to be farther apart as the circumference 

 of the thorax increases. Lateral organs are nowhere conspicuous but are 

 larger on the thorax than on the abdomen ; they have been located on all 

 segments, between notopodia and neuropodia. In the thorax they are 

 somewhat concealed by folds because they are retracted ; in the abdomen, 

 where they are non-retractile, they are visible as transversely elongated 

 papillae in a similar position as in the thorax but slightly behind the 

 uncinal ridge. 



Nephridial apertures number about 15 pairs; they are in the seg- 

 mental grooves about midway between notopodia and neuropodia. The 

 first is present between thoracic setigerous segments 9/10; they are con- 

 tinued posteriorly through anterior abdominal segments at least through 

 the eleventh one. They are subcircular, opaque white patches on the 

 anterior face of segments (pi. 55, fig. 5) ; it seems likely that they change 

 in character with age or maturity of individuals. 



Abdominal notopodia are well separated from each other. Already 

 from the first one they are separated by a distance about half as great as 

 the length of the long notopodial ridge. The distance between the 2 of a 

 pair increases farther back so that the tori are dorsolateral in position. Far 

 back, where the body diminishes in width, the tori come to be shorter but 

 the dorsal ones are still wide apart. Neuropodia are at first very long but 

 well separated from each other midventrally; they are ventrolateral in 

 position. In a far posterior region they also decrease in length and the 2 

 of a pair approach each other medially. The ridges are only slightly 

 raised above the surface of the body, but are not inflated as in D. lum- 

 bricoides (see above). 



Branchiae are retractile, branched structures. They are first present 

 from the thirteenth segment and continued posteriorly nearly to the end 

 but on the last few slender segments where parapodia are hardly visible, 

 they have not been distinguished. They emerge from a pore immediately 

 above the neuropodial ridge and come to be large, dendritically branched ; 

 the first division is dichotomous, resulting in a pair of short main stems; 

 subsequent branching is irregular. Where best developed there may be 30 

 or more distal filaments. 



Abdomnial hooded hooks have a thick node and a long slender shaft 

 between it and the base of the hood. Neck and shoulder regions are well 



