266 



8UBANTARCTIC ISLANDS OP NEW ZEALAND. 





[Oligochaeta. 



The dorsal gap (dd) is about one-third the circumference of the body. 



The clUellum covers the whole surface of segments 12, 13, and J 14 ; its 

 boundaries are quite sharply marked, and are especially well seen when the body- 

 wall is stained and mounted entire. The anterior margin crosses behind the male 

 pores. 



There are two pairs of male pores, both on the 11th segment, on a low papilla. 

 The anterior are immediately behind the ventral chae- 

 tae ; the posterior are quite close to the hinder margin 

 of the segment. 



There are two pairs of oviducal fores, large and 

 slitlike, in line with the ventral chaetae at 12/13, 13/14, 

 as in the genus Haplotaxis. 



The single pair of spermathecal pores is at the side 

 of the body, at 6/7. 



Interned Anatomy. 



The septa behind 7, 8, 9, 10, and 11 are slightly 

 thicker than the posterior ones. 



The short pharynx occupies 2, 3. There is no giz- 

 zard ; this I specially looked for, since Michaelsen has 

 pointed out that the only difference between Pelodrilus 

 and Haplotaxis is the presence of a gizzard in the latter. 



The oesophagus is straight, and has no dilatations. 

 The intestine commences in 17. 



Septal glands in 5, 6, 7, and 8. 



There are no enlarged hearts, though vascular loops are present as usual. 



The nephridia commence in 8, occur in 9, 10, are absent in 11, 12, 13, 14, and 

 resume in 15, 16, &c. 



The two pairs of testes and funnels are in 10, 11. The funnels are large and 

 flat, except at the ventral margin, which is curled upwards below the exit of the duct. 

 In contrast with the preceding species, the whole back of the funnel is attached to 

 the septum. The sperm-ducts are not convoluted (Plate XI, fig. 15). The anterior 

 duct, after perforating the septum, passes obliquely upwards and backwards in a 

 straight line, so that it is cut for nearly its entire length in a longitudinal section ; 

 then it forms two or three small undulations before returning parallel to its former 

 course downwards and forwards along the posterior surface of the chaetal muscles 

 to the body-wall, to open by a small pore just behind the ventral chaetae of seg- 

 ment 11. The posterior sperm-duct, after perforating the septum 12/13, takes 

 a similar course, and opens to the exterior close in front of the intersegmental 

 furrow 11/12. The septum 11/12 is here in front of this furrow, so that internally 

 the pore would be said to belong to the 12th segment, but externally the furrow, 

 though but slight just here, can be traced across the ventral surface, and becomes 

 quite deep. There is no doubt that this pore lies in front of this furrow. 



In segments 11 and 12 — i.e., on each side of the septum separating them — is 

 a great gland on each side of the body, opening on to the flat papilla mentioned in 

 the account of the external anatomy. This copulatory gland, like that in P. ignatovi 



Pei,odbilok aucklandicus. 



View of the genital region. 



a', tfl, the male pores ; 6', 6*, the 

 two pairs of oviducal j)ore8. o'^ lies 

 in a dotted area, which represents 

 the o])ening8 of an internal copula- 

 tory gland or prostate. 



