210 POLYDORA CAULLERYL 



The head has smaller prostomial processes than in P. flava and the median ridge 

 appears to pass backward to the fourth, bristled segment. Neither eyes nor pigment are 

 visible in the preparation, which consists of a fragment of the anterior region. The 

 anterior end differs from that in P. flava not only in the small prostomial process, but in 

 the conical outline, for the peristomial supports taper forward so as to make the anterior 

 end conical instead of the boldly convex lateral region on each side as in P. flava. The 

 arrangement of the bristles in the first four segments appears to be typical, though tliev 

 are somewhat shorter than in P. flava and P. ciliata, and the groups in the dorsal division 

 are clearly differentiated. 



The fifth foot (Plate C, fig. 9) is distinguished by the large size and conspicuous 

 condition of the dorsal capillary bristles, which are six in number, for the expanded tip is 

 bent at an angle to the shaft and the tapered end is again curved, thus giving the aspect 

 of a pointed bill-hook. The great hook-like bristles dilate from the base upward for fully 

 two-thirds of their length, then slightly diminish to the throat, from which a short tip 

 comes off at considerably more than a right angle, and soon ends in a bifid stumpy tip 

 (Plate OVI, fig. 4 6), characteristically different from that of any other species. In some 

 views a cavity appears in the centre of the tip, with the short points guarding its boundary. 

 Six or seven occur on each side, but the tips of only four or five project from the surface. 

 The bifid tip is well shown in the developing forms. The ventral capillary tuft is consider- 

 ably smaller than the dorsal, but the type of tapered bristles with a short tip is maintained 

 on a diminished scale. 



So far as could be observed the branchiae appeared on the seventh or eighth bristled 

 segment, and so with the hooks (Plate CVI, fig. 4 c), which do not differ materially from 

 those of P. ciliata; the curve of the shaft is similar, but the main fang seems to form a 

 larger angle with the neck and the spike on the crown is less erect, but these differences 

 may be partly due to position. The dorsal lamella of the foot appear to be small. The 

 body terminates posteriorly in a four-lobed process, the two dorsal being the larger (Plate 

 XCVIII, fig. 13). 



This species is due to the acuteness of Jacobi, who wrote his inaugural dissertation 

 on the Polydora3 of Kiel Bay. 



Mesnil (1897) observed four eyes and an intermediate pair. The tips of the great 

 hook-like bristles of the fifth segment, he states, resemble those in P. polybranchia. 



4. Polydoea Oaulleeyi, 1 Mesnil, 1897. Plate C, fig. 8— fifth foot; Plate CVI, figs. 



5 — 5 d — bristles and hooks. 



Specific Characters. — Prostomium forms a smoothly-rounded anterior termination 

 projecting a little in front of the rounded lobes of the peristomium. Median ridge 

 slightly contracted behind the anterior end, and passes backward to the fourth bristled 

 segment. Body tapers in front only from the fourth bristled segment to the snout, the 

 rest to the twenty-fifth segment having nearly parallel sides. The fifth bristled segment 

 is fully in a line with the others. Branchiae appear on the seventh or eighth bristled 

 segment. The first foot has both a dorsal and a ventral lamella, but only ventral bristles. 

 1 Named after the distinguished Professor of the Sorbonne, Paris. 



