Gatty Marine Laboratory, St. Andrews. 1^9 



double series of black dots appears — caused by the central 

 stalk of each spatulate bristle. 



The anterior tufts of simple bristles (at and after the ninth) 

 are characteristic when contrasted with the northern Chone 

 infundibuliformis from Greenland ; for in lateral view the 

 shafts are curved, constricted as they approach the wings, and 

 the tip leaves the shaft at an angle, whilst it is finely 

 tempered and bordered with the narrow wings. In antero- 

 posterior view the constriction at the upper end of the shaft is 

 distinct, the base of the tip (continuation of the shaft) being 

 considerably broader. On the other hand, the bristles of 

 the Greenlandic species are much more slender, the tips 

 longer and more attenuate, and the wings just visible. The 

 constriction of the shaft below and its dilation above the 

 commencement of the tip scarcely attract notice. 



A change occurs at the ninth bristle-bundle, which is now 

 ventral to the row of hool<s, for all have tapering tips with 

 the serrate wings, and slant upward and backward. The 

 succeeding tufts are equally powerful, and have the same 

 direction till the posterior liftli is reached, and there the 

 bristles graduall)'^ assume an oj)po5ite direction — that is, 

 downward and forward. These posterior bristles are longer 

 and smoother, presenting no serrations, and the terminal 

 wings narrower, so that the shaft is more conspicuous. The 

 free portion of the bristle increases disproportionately, the 

 shaft being little more than a quarter of the length. Further, 

 whilst the bristles of the anterior region are in front of the 

 median ring of the segment and the hooks behind it, 

 the posterior bristles are more nearly in a line, though still 

 anterior to the row of hooks. Generally speaking, the 

 anterior bristles have most of their shaft below the skin and 

 a shorter tip, whilst the posterior have a short shaft under 

 cover and a long tip — conditions doubtless connected with 

 their functions. 



The rows of hooks commence on the second bristled 

 segment to the ventral side of the bristles, and the first 

 seven — that is, those of the anterior region — are longer and 

 more boldly marked than the succeeding, appearing like 

 minutely dotted dark lines under a lens. The hooks are 

 arranged alternately in a double row, but toward the ends 

 of the row, especially ventrally, appear to form a single 

 series. Each presents a long, curve(l, striated shaft, deeply 

 inserted into the muscular coats, and tapering from the 

 w'ell-marked shoulder to the base. The neck is translucent, 

 finely striated, especially superiorly, narrowed above the 

 shoulder, and again slightly dilated as it approaches the 



