Oligochaeta.] SUBANTARCTIC ISLANDS OF NEW ZEALAND. 283 



of them, viz., intermedia, Beddard* — but the genus also includes numerous species 

 from Australia. Two of the New Zealand species, D. gigantea and D. shakespeari, 

 Benham,t have recently been removed from this genus by Michaelsen,{ owing to 

 their micronephric character, and placed in a new one, Spenceriella, with two or 

 three Australian species ; but, as I noted in my account of the species, the nephridial 

 funnel of the meganephridium still remains, and it does not seem to me at all a satis- 

 factory feature to adopt as a generic character. Most of our species of Diporochaeta, 

 in having only two pairs of spermathecae, differ from the Australian species, which 

 have four or five pairs. 



Diporochaeta heIophila,§ sp. nov. (Plate XI, figs. 30-33.) 



This small species is remarkable for the very dark chocolate-brown coloration 

 of the skin, and for the peculiar distribution of the pigment. The usual position of 

 the pigment in earthworms is in the connective tissue of the circular muscle-layer ; 

 but in this worm, in addition to this, there is a fine brown pigment amongst the 

 epidermal cells, close to the surface, and apparently in the columnar cells. The 

 pigment in the circular muscles consists of black granules, and is especially abundant 

 in the anterior 11 segments. Thirdly, and posteriorly to the 11th segment, there is 

 a peculiar flaky brown pigment in the somatic coelomic epithelium. This extends 

 all the way round the body in these segments, whereas the other pigments are con- 

 fined to the dorsal half of the body (Plate XI, figs. 30, 31). This flaky pigment 

 appears to lie in the superficial portion of the vesicular cells, and in segments 13-18 

 there are three to five rows of cells forming a very conspicuous layer in sections 

 (Plate XI, fig. 32). The colour is not, therefore, limited to the anterior portion of 

 the body nor to the dorsal region, but is only a little paler in the hinder end and 

 on the ventral surface. The chaetae are set in pale spots, which may be almost 

 white. The clitellum is uniformly paler brown. 



Dimensions. — The length of the mature worm varies from 26 mm. to 47 mm., 

 with a diameter of 1 mm. ; there are from 47-98 segments, an unusually wide range. 



The chaetae are 24 per segment, though in the hinder part of the body I counted 

 only 20 in a trans-section. They are very noticeable, owing to the white dots that 

 surround their bases. The interchaetal spaces are somewhat irregular, but sub- 

 equal ; the dorsal gap is greater than the ventral, in the proportion of 5 to 3, the 

 latter about twice an interchaetal gap. 



The clitellum occupies the 14th to 17th segments, the anterior two of which 

 are completely encircled. 



Genital Pores, &c. — The male pore, on the 18th, is in line with chaetae he (in 

 reality, it is in the line of h, but, as in other species, the ventral chaetae are thrust 

 outward in these segments to the level of c in neighbouring segments) ; being white 

 in colour, it is more readily recognisable than usual. The oviducal pore, likewise 

 white, is in front of chaeta a. 



* Beddard, Proc. Zool. Soc., 1890, pp. 55, 56. 



t Benham, " An Account of some Earthworms from Little Barrier Island," Trans. N.Z. Inst., 

 xxxviii, p. 252, 1906. 



X Michaelsen, Die Fauna S.W. Austral., p. 161. 

 § Swamp-lover. 



