COMPLETE HARTMAN: POLYCHAETES FROM CALIFORNIA 101 



size. Hooded hooks are first present from the eighth, instead of seventh, 

 setigerous segment. The modified fifth segment has a double, instead 

 of single, row of modified spines. In the specimen reported, the first 

 setigerous segment is inconspicuous, located dorsolaterally and at the 

 level of the prostomial eyes. Branchiae are first present from the 

 eighth, or first uncinigerous, segment. 



Family MAGELONIDAE 



Genus Magelona Midler, 1858 



Type M. papillicornis Miiller, 1858 



Magelona sacculata, new species 



Plate 18, figs. 1-7 



Magelona sp. Hartman, 1955a, p. 176. 



Collections. Hundreds of individuals come from shallow ocean bot- 

 toms, chiefly in depths of 20 to 40 meters, off southern California, 

 from Point Conception to south of the Mexican border and in sediments 

 of olive green silt to gray sand. The type is selected from VELERO 

 IV Sta. 2311 on the San Pedro shelf area; others are from the Santa 

 Monica Bay shelf, and adjacent areas to the north and south. The 

 best represented stations (see data in Barnard, Hartman and Jones, 

 1959) are the following: 4744 with 158 specimens, 4819 (150), 

 4843 (102), 4842 (100), 5185 (51), 4840 (47), 4758 (47), 4743 

 (49), 5043 (72), 4844 (56), 4787 (25), 4759 (22) and many others. 



Length of a larger individual is 20 to 30 mm; width is 7 mm or 

 less. The body is threadlike and widest in the region of the palpal bases; 

 it tapers posteriorly and consists of 100 or more segments. The prosto- 

 mium is rounded in front, has a long, triangular median low ridge 

 without lateral horns (PI. 18, fig. 1) and a pair of weak, transversely 

 ridged, lateral areas. The proboscis, sometimes everted, is a smooth, 

 subspherical pouch. Paired palpi are long, coarsely papillated along the 

 sides and most conspicuously in their distal three fourths; there are no 

 eyes. The posterior end of the body terminates in a broadly rounded 

 anal end with a pair of short, laterally directed processes (PI. 18, 

 fig. 2). 



The first segment is a smooth, broad ring slightly longer than the 

 next, or first parapodial, segment. The next 9 segments are setigerous, 

 and have laterally directed biramous parapodia with foliaceous lobes 

 above and below. The setal fascicles are spreading and have setae of 

 one kind; they are long, slender and taper distally. 



