POLYDORA CAULLERYL 211 



The fifth foot is prominent, and dorsally bears a tuft of strong capillary bristles with 

 flattened, winged, and rather short tapering tips bent abruptly backward. The great 

 hook-like bristles have the points of the main fang directed backward and slightly 

 upward ; shaft broad, flattened, dilating from the base to the distal third, where a slight 

 backward curve and diminution occurs to the throat ; but, whilst the inner curve is even, 

 the outer has a slight projection or shoulder rather below the level of the throat. The 

 strong main fang comes off at a little more than a right angle, and the point is by no 

 means acute. The crown of the fang has the upper surface flattened and prominent 

 on each side, whilst superiorly a comb-like crest with a serrated edge curves from the 

 back of the crown almost to the point of the fang. Winged hooks of the ordinary form 

 with a sharp main fang and a spur on the crown above commence in the ventral division 

 of the seventh segment. 



Synonyms. 

 1897. Polydora Caulleryi, Mesnil. Bull. sc. Fr. et Belg., t. xxx, p. 88, pi. iii, figs. 12—16. 

 1909. „ Carazzi, Mcintosh. Ann. Nat. Hist., ser. 8, vol. hi, p. 172, pi. y, figs. 4—6. 



Habitat.— A large example occurred in the shale at the Castle Rocks, St. Andrews, 

 February, 1865. A single specimen obtained between tide-marks at Lochmaddy, North 

 Uist, August, 1865. 



Elsewhere it has been procured on the shores of France (Cap de la Hague), Mesnil, 

 who found his specimen on a Platycarcinus pagurus covered with Pomatoceros triquater. 



The head characteristically differs from that of any other species of the genus, in 

 that the anterior end of the prostomium forms a smoothly-rounded prow projecting 

 very little in front of the rounded lobes of the peristomium at the sides. The median 

 ridge is slightly contracted behind the rounded anterior promontory, and, passing back- 

 ward, terminates at the fourth bristled segment. The mouth opens beneath as a long 

 (acute) triangle, with the prominent lip on each side. No eyes are visible and no pigment. 



The tody, of which there is only the anterior region of twenty- five or twentv-six 

 bristled segments, tapers from the fourth bristled segment to the snout, the rest having 

 nearly the same diameter, and it is a feature that the fifth bristled segment is fully in a 

 line with the others, its antero-posterior diameter being as usual greater than in the 

 segments adjoining. 



The first foot has both a dorsal and a ventral lamella, but only a tuft of ventral 

 bristles, the tips being directed rather outward than backward, the convexity of the curve, 

 however, being forward. They are shorter than those immediately following. The 

 second, third, and fourth feet have lamellae and dorsal and ventral bristles agreeing with 

 those of other forms. 



The fifth foot (Plate C, fig. 8) is remarkably prominent, and dorsally bears a strong 

 tuft of capillary bristles, the flattened, winged, and rather short tips of which curve 

 somewhat abruptly backward. The great hook-like bristles have the points of the main 

 fang directed backward and slightly upward. Each consists of a broad flattened shaft 

 (Plate CVI, figs, bb and 5c), which dilates from the base to the distal third, where a 

 slight backward curve and diminution ensue at the throat, but, whilst the inner outline is 

 even, the outer shows a slight projection situated rather below the throat, which is by no 



