274 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 15 



alcohol. Branchial tips and the foliaceous neuropodial flanges (often with 

 ruffled margins) on the ventrolateral side of the abdomen are often dark- 

 ly pigmented, with the color concentrated as clusters of minute dark 

 spots, as shown by Johnson (1901, pi. 10, fig. 108). Branchiae are small 

 at first and gradually increase in size to form flat, dorsally directed 

 processes with an asymmetrical subapical swelling (fig. 3). Where best 

 developed in abdominal segments, they are fimbriated along their lateral 

 margins and the fimbriae are not visibly continued across the middorsum 

 of the body. 



Thoracic setae are all slender and distally pointed ; those in neuro- 

 podia form fuller tufts than those in notopodia. The upper ramus is 

 supported by about 5 yellow acicula in a close bundle; each one is very 

 slender, sickle-shaped at the distal end and has a long, pointed tip (fig. 

 1). Transitional parapodia have about 4 notopodia and 6 similar neuro- 

 podial acicula (fig. 2). Thoracic setae (fig. 4) are shorter and thicker 

 (fig. 9) than abdominal setae (fig. 11). All have transverse rows of 

 spinelets (figs. 6, 7) that number 10 to 12 in a row (fig. 5). Furcate 

 setae are present in abdominal notopodia (fig. 3), located at the inferior 

 end of the setal fascicle; they number 2 to 5 in a bundle; their tines are 

 unequally long and the shaft is spinous (fig. 8). Lateral organs are 

 clearly visible in abdominal segments ; they are provided with short stiff 

 hairs. 



Many individuals taken in quantitative samples from San Pedro 

 Basin of southern California in 13 to 293 fathoms (Hartman, 1955) are 

 uniformly alike in that the transition from thorax to abdomen is at 

 setigerous segment 15/16; branchiae are present, though small, on the 

 last several thoracic segments and become larger thereafter; abdominal 

 neuropodia have the foliaceous flange like those from more northern 

 localities. The ovigerous region comprises abdominal segments 7 to 26. 



The pygidium is collarlike and has a pair of long slender filaments 

 attached at the dorsolateral margin. 



Specimens reported as Scoloplos elongata (Treadwell, 1914, p. 199) 

 from Salmon Bay, Puget Sound, have been found to agree with Haplos- 

 coloplos elongatus; others coming from Tomales Bay and Coronado, 

 California, are here referred to Scoloplos (Scoloplos) acmeceps. Aricia 

 sp. Treadwell (1914, p. 199) from San Diego, California, is also re- 

 ferred to Haploscoloplos elongatus. H. kerguelensis Berkeley and Ber- 

 keley (1941, p. 41) from southern California may also be referred to 

 what I am calling H. elongatus, since it comes from the same geographic 

 area. 



