Oligochaeta.] SUBANTARCTIC ISLANDS OF NEW ZEALAND. 273 



dd, so that the formula is aa <, db <.hc ; he = cd ; aa = ^ dd. In this respect it is 

 intermediate between a typical N. aucklandicus and N. campbellianus. It has tuber- 

 cula on 9 and 10, median in position ; while those of 17, 18, 19, and 20 are paired. 

 The spermathecal duct is much wider and the ampulla less dilated than in the typical 

 specimens, although the organ is filled with spermatozoa. These differences are, 

 however, overshadowed by the undoubted agreements in such matters as the size 

 and shape of the penial chaetae and other diagnostic features ; so that, while not 

 deserving specific separation, it seems desirable to distinguish it by a name. I 

 therefore associate with the variety the name of Captain Bollons, of the Government 

 steamer " Hinemoa," a keen naturalist himself, who did all in his power to further 

 our aims and to assist us in every way during the expedition. 



Var. pallidus, n. v. 



Other divergent individuals were found in logs on Enderby Island, in company 

 with N. camphellinnus. 



This variety is a minute, colourless form, only 23 mm. in length by 3-25 mm. 

 in diameter ; contains only 76 segments, though it is quite mature, with a half 

 clitellum covering segments 14-16, and tubercula pubertatis as follows : Paired on 

 10, 20 ; median on 16 and 18. It agrees in its chaetal formula and in its general 

 anatomy, including the penial chaetae and spermatheca, with N. aucklandicus. 



Notiodrilus campbellianus, Benham. 



1905. Trans. N.Z. Inst., xxxvii, p. 288. 1907. Microscolex campbellianus, 

 Michaelsen, Die Fauna S.W. Austral., p. 143. 



Like the foregoing, this species was originally collected by Dr. Cockayne, who 

 discovered it on the sea-shore on Campbell Island. 



It is much smaller than the foregoing, and appears to be less common ; perhaps 

 this is only because its colour, being darker and harmonizing more nearly with the 

 logs under which it is usually found, renders it less noticeable. The dark chocolate- 

 brown pigment is distributed almost over the entire body, the lower side being nearly 

 as dark as the upper, and the hinder as the anterior end. The chaetae are set in 

 white spots, which are much more conspicuous and are absolutely larger than in 

 N. aucklandicus. 



The length varies from 23 mm. to 45 mm., while one well-preserved specimen 

 extended to .52 mm. The number of segments varies from 65 to 85. 



The chaetal formula differs from that of the preceding species chiefly in the 

 much greater separation of the dorsal chaetae {dd), the remaining spaces being ap- 

 proximately equal, though ah is less than cd. 



The tubercula pubertatis exhibit the same sort of variability as before. It 

 appears that a pair on 17 and 19 are constant. An additional pair often occurs on 

 the 21st, and more rarely on the 22nd. In one individual they are also present on 

 14th and 16th, and in one case the 8th and 9th also bear tubercles. 



The nephridiopore is in the same position as in the preceding. 



Internal Anatomy. 

 Although I can detect no gizzard, yet in sections there is visible a small one 

 in the 6th segment, concealed by the pharyngeal muscles and glands. The oeso- 

 18— S. 



