SOLOMON ISLANDS, THE NEW HEBRIDES, AND THE LOYALTY ISLANDS. 191 



This example measures 56 mm. in length and consists of some 90 segments ; of the 

 remaining specimens the largest was not more than 38 mm. in length. The smaller 

 specimens were all collected on the banks of a rivulet in New Britain ; the largest 

 example bears the label " Gazelle Peninsula, New Britain." 



This species of Perichaeta is coloured above of a bluish violet tint. My obser- 

 vations upon the species chiefly relate to some of the smaller specimens which 1 

 examined as to external characters as microscopical objects and by longitudinal 

 sections. But the largest specimen was dissected and was found to differ in no point 

 of importance that I could ascertain from the smaller individuals save in the number 

 of the genital papillae. These papillae (Fig. 4) differ somewhat from individual to 

 individual and the largest number were not present in the largest specimen. In 

 tli.it specimen their arrangement was as follows: — On each of segments XX — XXII 

 tin iv was a long transversely elongated papilla median in position and unpaired. In 

 a smaller example the same papillae were present and in addition one upon each of 

 nt< XVII and XVIII as well as upon XII and XIII. 



The clitellum occupies segments XIV — XVI; the last segment appears to always 

 possess a complete circle of setae at the margin where the glandular development of 

 the segment ends; in the I pecimen the XVth segment also had a complete 



circle of setae. In a smaller individual mounted as a microscopic object I could see 

 no setae upon the XVth segment ; but in addition to those upon the XVIth were 

 three setae on each side of the oviducal pore upon the XlVth. 



In this latter specimen the setae upon a selected series of segments were present 

 in the following numbers: VIII, 37; XIII, 47; XVII, 46. 



There are in this specimen 10 setae between the male pores. 



The septa dividing segments VII and VIII are thick: but those dividing segments 

 IX and X are especially thickened. They are the thickest septa of all. Contrary 

 to what is apparently sometimes found in this genus the septum between segments 

 VIII and IX was present, though thin. In sections which did not embrace the 

 gizzard this septum was seen to lie straight across the body-cavity and to bound a 

 space — the coelom of the VHIth segment — very much less than that bounded by the 

 thick septum immediately following it. But in sections in which the gizzard was 

 shown in position the septum was convex backwards so that the gizzard chiefly lies 

 in the Vlllth segment. 



Caeca are present. The last "hearts" are in segment XII. 



The reproductive organs are mainly remarkable for the fact that there is but a 

 single pair of testes, sperm ducts and sperm sacs. The testes lie together with the 

 funnels lying opposite to them in a special sac, the sperm reservoir. The single pair 

 of sperm sacs are in segment XII. They are racemose in appearance. The spermi- 

 ducal glands extend through three segments, i.e. XVII— XIX. The duct is short and 

 has no terminal sac. The spermathecae are present to the number of four pairs in 

 segment VI— IX. Each has a single tubular diverticulum. It seemed to me that the 

 sperm duct did not open into the duct of the spermiducal gland until a little way 

 in front of the external aperture of the latter. Dr Benham has found the same 

 state of affairs to characterise P. malamaniensis and quotes my own discovery of the 

 union between the male duct and the duct of the spermiducal gland at a late point 



