SOLOMON ISLANDS, THE NEW HEBRIDES, AND THE LOYALTY ISLANDS. 189 



specimens papillae exist near to the spermathecal pores as well as in the neighbour- 

 hood of the male pores. In the larger example, whose measurements are given above, 

 the arrangement was this: — On segment XIX there are three papillae lying side by side 

 in the middle of the segment, a little in front of the line of setae. In the two following 

 segments there are, on each, five papillae, one on each side being added to the three of 

 the XlXth segment. On the XXIInd segment only two of these five were visible, those 

 on the outside (left side). The anterior sets of papillae lie on segments X, XI; on the 

 Xth segment there is a row of four papillae and six on the Xlth ; these papillae lie in 

 every case in front of the setae of their segments. 



In the smaller individual from Narowol each of segments XIX — XXI has a 

 symmetrical row of four papillae. Those upon segments X, XI are fewer and not sym- 

 metrical ; there are three on the latter and four on the former. 



In the specimen of Perichaeta solomonis from New Georgia, the disposition of the 

 papillae was a little different. On each of segments XIX — XXII were four symmetri- 

 cally placed papillae, save on the last of these segments where one was missing. 

 There were also two or three papillae on segments X and XL 



The porophores bearing the male pores are very conspicuous in this species. 

 They are much raised and of a whitish colour. The actual male pore is in the line 

 of setae, and the two are separated by a line of fifteen setae. Anteriorly to each 

 pore is a sucker-like papilla. 



This is a stout and strong species of Perichaeta ; corresponding to these character- 

 istics the septa and the muscular development generally within the body-cavity is 

 pronounced. Behind the gizzard are five rather stout septa which are to some 

 extent tied together by muscular bands. From the posterior as well as from the 

 anterior margin of the gizzard itself arise half a dozen broadish muscular bands which 

 bind it to the following septum or to the body-wall. From the pharynx radiate out 

 a large number of slips of muscle which for the most part perforate adjacent septa 

 and are inserted on to the body-wall. It is interesting to notice that the septum 

 separating segments VIII and IX is present and is indeed moderately stout. In so mam- 

 cases this septum has been recorded as absent that there can be little doubt that 

 it is not always represented; but in one or two species its existence has been mentioned 

 by several authors. Benham, for example, has especially noted its presence in Perichaeta 

 arturi 1 . The bulk of the gizzard in Perichaeta solomonis lies in front of the septum 

 and belongs therefore to segment VIII. I find in this species, as did Benham in 

 P. arturi, a pair of hearts corresponding to this segment. The intestine has caeca. 



The most noteworthy point about the vascular system that I observed was the 

 fact that the last pair of hearts are in the Xllth segment and not, as is so generally 

 the case, in segment XIII. 



Perichaeta solomonis is also remarkable for the fact that it possesses three pairs 

 of sperm-sacs instead of the more usual two. These lie in segments X— XII ; they 

 are large, and the first pair are racemose in appearance. The egg-sacs in the XlVth 

 segment are large and conspicuous. The spermiducal glands (Fig. 6) are cut transversely 

 into three lobes lying respectively in segments XVIII, XIX, XX; each lobe is again 



1 I also describe it here in P. pacinca (p. 191). 



