SOLOMON ISLANDS, THE NEW HEBRIDES, AND THE LOYALTY ISLANDS. 187 



As to the setae of this species they do not differ markedly in size on different 

 segments of the body or on different parts of the same segment. Their numbers on 

 certain segments are as follows : 



X, 46 ; XIII, 50 ; XVII, 55 ; XXV, 54. 



I counted 7 setae between the male pores. 



As to the internal structure of this species of Perichaeta, the following facts 

 appeared to me to be specially noteworthy. 



There are five stoutish septa lying behind the gizzard, the last of which separates 

 segments XIV and XV. 



The last of the contractile "hearts" lies in segment XIII. 



The gizzard is large ami appears to lie in segments VIII, IX; I could find 

 no septum separating these segments. The intestine begins in segment XVI. The 

 caeca arise in XXVI and extend forward through three segments. 



In the region of the intestine I found numerous racemose " lymph glands," lying 

 as usual on either side of the dorsal vessel. 



The reproductive organs are upon the usual plan. Two pairs of sperm sacs lie 

 in segments XI and XII. The two of each side of the body are connected by a 

 sperm reservoir, which projects into the tenth segment, and encloses the funnels of 

 the sperm ducts. The two sperm reservoirs seem to be quite distinct, and between 

 them runs the nerve cord. Corresponding to the sperm sacs are two comparatively 

 large egg sacs in the XlVth segment. The large size of these structures in Perichaeta 

 is often noticeable ; but they have not been recorded in all species. In Perichaeta 

 npiihiensis they are of an elongate pear-shaped form. The spermathecae (Fig. 8) are 

 present to the number of two pairs lying in segments VIII and IX. Each has a 

 single diverticulum, which is longer than the pouch of which it is an appendix. The 

 diverticulum is plainly divided into a region for the storage of the sperm and a 

 duct. The extreme end of the diverticulum is again divided by a constriction and 

 is dilated ; this however is possibly only a temporary condition caused by the presence 

 in it of abundant sperm. The spermiducal gland lies in three segments in front of 

 its external orifice. The duct is unprovided with a terminal sac. 



Perichaeta Esafatae, n. sp. 



One example of this, which I regard as a new species, was collected on the 

 island of Esafate in the New Hebrides. As there is but this one specimen, my account 

 of the species will have to be less complete than is desirable. 



The worm measures 115 mm. and consists of 105 segments. 



The colour dorsally is purple. 



The clitellum occupies the usual segments and is devoid of setae. 



The most characteristic feature of this species, as is so often the case in the 

 genus Perichaeta, is the arrangement of the genital papillae. These are numerous in 



27—2 



