178 Polychcetous Annelids Collected at Friday Harbor, 



retaining essentially their earlier character. A number of aciculse (4 in the one drawn) 

 occupy the center of the setal lobe. One of these was drawn out into a slender, curved, 

 acutely pointed tip, and it is probable that the others had originally this structure, 

 which had been broken off. There is a tuft of needle setse in the dorsal cirrus. 



The setse form a dense tuft of four kinds: dorsalmost is a small tuft of very slender 

 pectinate; next to these simple ones, long and very sharp-jx)inted, with the terminal 

 portion very much flattened and provided with lateral wings; ventral to these, some 

 of quite similar form, but with the terminal part broader and shorter than in the dorsal- 

 most ones. Under high power they show a finely pilose character, as if fine hairs were 

 thickly distributed over the terminal region. At the ventral end of the series is a 

 bundle of compound setae. 



The thirty-fifth parapodium (fig. 26) has a conical setal portion with a rounded lobe 

 on its anterior face. Dorsally it carries a gill which is larger than the dorsal cirrus 

 and extends to beyond the dorsal midline. Long needle aciculae extend into the dorsal 

 cirrus. The acicula* are of two kinds: (1) slender forms with the free end terminating 

 in a very sharp point (fig. 27); (2) a much heavier form with apical and subapical 

 teeth narrowing into a neck just proximal to the subapical tooth and then broadening 

 into the shaft (fig. 28). Only one of each is drawn in figure 26, but there were two of 

 one and four of 2 in the actual specimen. In place, the larger one looked as if hooded, 

 but this was evidently due to the fact that it lay in a slight depression, so that it was 

 partly covered by a transparent fold of the outer skin of the body. 



The semicompound setae (fig. 29) at first appear compound, but closer examination 

 shows that what looks like a terminal joint is really not completely separated from the 

 basal. There is a large terminal tooth and there are two unequal subterminal ones, 

 with a hood covering them all, the apex of this hood thickened. The simple setae 

 (fig. 30) enlarge rapidly toward the apex and then narrow to an acute point. The com- 

 pound setae (fig. 31) are slender, with a smooth, pointed terminal joint without teeth or 

 hood. The pectinate setae (fig. 32) have long shafts with about 12 very slender teeth. 



The gills begin on about the twentieth somite, the most anterior ones smaller than 

 those farther back. There is never more than one branch (fig. 26). In the single 

 entire specimen the last gill was on the twenty-fifth somite in front of the pygidium. 



The jaw apparatus is extremely soft and delicate and difficult to remove without 

 injury. In the one figured the halves of the maxillae had fallen apart and the unpaired 

 plate had turned over (fig. 33). Normally the inner margins of the carriers are in 

 contact. Except for the dark pigmented patches indicated in the figure and the tips 

 of the teeth, all parts are thin and transparent. The carriers are triangular in form, 

 the forceps rather heavy and not much curved. Each proximal paired plate has 6 

 teeth, the distal paired has 10 on the right and 8 on the left. The unpaired has 7 

 well-developed teeth and 1 very small one. The mandible (fig. 34) has pointed lateral 

 wings and faintly marked concentric lines on the beveled portion. Near the middle 

 line each has a prominent dark band running lengthwise. 



Type in the American Museum of Natural History. 



Family SPIONID^. 

 Polydora calilomica Treadwell. 



Polydora californica Treadwell, 1914, Polychsetous Annelids of the Pacific Coast in the 

 Collections of the Zoological Museum of the University of California. Dniv. of 

 Calif. Pub. in Zoology, vol. 13, p. 203, pi. 12, figs. 23 to 29. 



This species was abundant in Newhall's lagoon at Friday Harbor and was collected 

 at False Bay. To the original description may now be added that of the pygidium, 

 which was absent from the specimens from California. This has the form of a broad, 

 very shallow funnel (fig. 35). 



