228 *" ENDEAVOUR " SCIENTIFIC RESULTS. 



On the underside the prostoniiuna presents a pair of rounded 

 lobes (? palps) immediately in front of the mouth (PI. xlii., 

 fig. 82). 



The p^ristomiumand nuchal segment are separated dorsally 

 and laterally by a furrow, but merge into one another ventrally, 

 as the furrow bends forwards on each side nearly at right 

 angles, and thus delimits a ventral lip which is marked by 

 longitudinal furrows. 



The peristomium is about twice the length of the nuchal 

 segment, whose lei;gth is equal to that of the first chstitigerous. 

 The parapodia of a few anterior segments have a rejDresenta- 

 tive of a dorsal cirrus in the form of a small rounded lobe 

 into which a small bundle of fine bristles enter. The feet as 

 seen from above under a dissecting lens have from the first 

 a long posterior lip, which is antero-j^osteriorly comjjressed 

 so as to be lamelliform ; it is quite narrow in a well preserved 

 specimen, but rather thicker in the other (PI. xhii., fig. 89). 

 In the latter this lip is bent upwards in many of the feet, but 

 in the other specimen its bluntly rounded apex is directed 

 outwards (PL xlii., figs. 86, 87) ; its upward bend is, I 

 think, due to pressure against the wall of the containing 

 tube. The upper margin is nearly horizontal, though it is 

 slightly concave, while its lower margin slopes upwards 

 from below. The feet in the first half-dozen segments 

 are smaller than the following. The posterior lip is curved 

 backwards in the greater part of the body. While the lip in 

 the anterior segments is much compressed and very thin, it 

 becomes, somewhere about the fortieth, shorter and thicker, 

 and this proceeds till it is in the jjosterior segments short 

 and quite thick (PI. xliii., fig. 89). The anterior lip Hkewise 

 changes somewhat in its form. Both lips are very vascular, 

 but the vessels in the posterior lip are more numerous and 

 more clearly seen owing to its thinness. 



The capillary chaetae, many of which are brown and 

 iridescent, joroject a good way beyond the larger lip, and 

 this especially in the case of the upper chsetse. In the 

 anterior 40-50 feet all the chaetae are flanged capilliforms, 

 bent upwards from a point just below the commencement 

 of the flange (PI. xlii., fig. 86). 



But at or about the 50th foot most of the lower capilliforms 

 are replaced by hooks, with a long hood formed by a pair 

 of wings (PI. xlii., fig. 84) ; and by about the 60th the upper- 

 most capilliforms are similarly replaced by one or usually 

 by two hooded hooks (PI. xlii., fig. 85). 



