Gatty Marine Laboratory ^ St. Andrews. 171 



than Pulydora jiava and the median ridge goes backward to 

 the 4th segment. The snout differs from most of the other 

 forms in its conical outline, since the peristomial supports 

 taper anteriorly. Jacobi describes and figures four eyes 

 on the median ridge between the tentacles, though they are 

 frequently absent. The arrangement of the bristles in the 

 first four segments appears to be typical, though they are 

 somewhat shorter than in Polydura ciliata or in P. Jluva, 

 and the groups in the dorsal division are clearly differentiated. 

 The fifth foot is distinguished by the large size and con- 

 spicuous condition of the dorsal capillary bristles (PI. V. 

 fig. 3), for the expanded distal region is bent at an angle to 

 the shaft, and the tapered tip is again curved ; thus the aspect 

 is that of a pointed bill-hook. The great hook -like bristles 

 (PI. V. fig. 2) dilate from the base upward fully two-thirds 

 of their length, then slightly diminish to the throat, from 

 which a sliort distal region comes off at considerably more 

 than a right angle and ends in a bifi.l truncated tip. Six or 

 seven occur on each side^ but the tips of only four or five 

 project from the surface. Jacobi * describes and figures those 

 of his i^olydora quadrilobata as ending bluntly with a right 

 and left spur and a thin guard or wing. The latter, however, 

 was not visible in this example, but may have been abraded. 

 The ventral tuft is considerably smaller than the dorsal, but 

 the type of bristle is maintained on a diminished scale. 



So far as could be ascertained in the fragmentary form, 

 the branchise commence on the 7th bristled segment, and the 

 hooks, which do not materially differ from those of Pobjdora 

 ciliata, on the 7th segment. Jacobi represents the anal 

 funnel as 4-lobedj but it was not present in the British 

 specimens. 



Langerhanst describes Po^ydora armata, from Madeira, 

 as having in the 5th segment two or three large hook-like 

 bristles with trifid tips, but his figure shows a blunt, curved 

 tip deeply cleft and winged, the outline being very different 

 from Jacobi's. The prostomium is bifid, and the peristomial 

 lobes are also blunt in front. The branchiae occur from the 

 7th to the 12th segment. Moreover, in the last five or six 

 segments brownish, stiff, straight, taperiug bristles are 

 present, thus diftering, he observes, from Keferstein's 

 F. cUiata, with which the branchise agree. The anal funnel 

 has a dorsal and a ventral hiatus. If figures can be relied 

 on, the tips of the large bristle-like hooks of the 5th segment 

 as well as the anal funnel differ from Jacobi's species, and 



* Oj).. elf. p. S. 



t Zt-itscli. f. w. Zonl. Bd, xxxiv. p. a-J. Taf. iv. fig. 5. 



12* 



