FROM THE MERGUI ARCHIPELAGO. 



259 



bv a transverse zigzag groove, which is caused by the regular 

 arrangement in this region of the rhomboidal areas of the 

 skin. 



The dorsal surface of the body is also marked by patches of 

 pigment which have a regular and characteristic arrangement ; 

 each segment has a median stripe which widens out anteriorly 

 into a triangular patch ; the transverse furrow marks the junction 

 between the triangular patch and the narrow stripe; posteriorly 

 two curved pigment-bands pass one on each side along the 

 furrow separating the dorsal from the lateral portions of the 

 segment. The whole pigmented area has, as Horst has remarked 

 in the case of Chloeia parva*, a marked resemblance in shape to 

 an anchor. Each segment has also a broad pigmented band on 

 the anterior side of the parapodial outgrowth ; in the anterior 

 segments of the body this latter band is continuous with the 

 curved lateral pigmented bands ; in these segments also there is 

 a short pigmented streak behind the parapodial outgrowths ; in 

 the posterior segments this streak gradually dies away. 



The ventral surface of the body is comparatively smooth, with 

 the exception of a few of the anterior segments which bound the 

 mouth ; these are much wrinkled by longitudinal furrows ; the 

 third and fourth segments of the body are fused in the middle 

 ventral line into a rounded projection which bounds the mouth 

 posteriorly ; this process is greatly furrowed ; the middle ventral 

 line of the body is marked by a distinct and rather transparent 

 line which corresponds to the nerve-cord. 



The caruncle extends back as far as the fourth segment, 

 but its posterior end is free, and it is not attached to this 

 segment nor to much of the third ; the caruncle bears a longi- 

 tudinal pigmented stripe. 



The setae are much more abundant in the neuropodium than 

 in the notopodium ; they are of considerable length in the former, 

 and have everywhere a white silky appearance. 



The dorsal setae (fig. 2) are all of one kind ; they are stout, 

 and serrated at the free extremity. The general aspect of these 

 setae is in fact closely similar to that of other species. The 

 extreme tip of the seta is often of a yellow colour, and slightly 

 serrated on the margin which bears the lateral teeth, before the 

 commencement of the latter ; below the lateral serrations and on 



* ' Notes from the Leyden Museum,' vol. viii. p. 168. 



