270 SUBANTARCTIC ISLANDS OF NEW ZEALAND. [Oligockaeta. 



It is true that in some of the species of PerionycheUa he writes that the testes and 

 sperm-fxinnels are " apparently free," while for the species of Perionyx he states 

 that they are enclosed in "testikelblasen." 



Notiodrilus haplocystis, Benham. 



1901. Acanthodrilus haplocystis, Benham, Trans. N.Z. Inst., xxxiii, p. 130. 

 1907. Eodrilus haplocystis, Michaelsen, Die Fauna S.W. Austral., Oligo- 

 chaeta, p. 141. 



I obtained a number of individuals on the occasion of each of my visits to the 

 Snares, in February and November, 1907. I am thus able to add the following 

 facts to my original account. 



It is very common under stones and in the soil. 



Colour. — Orange-brown ; the darker segmental ring referred to in my former 

 account is not so striking in fresh as in preserved specimens, nor so marked in those 

 in formol as in those in alcohol, but when fully extended a paler band is recognisable 

 in the anterior region of each segment. 



Dimensions. — The largest individual measures 460 mm. by 6 mm. ; the smallest 

 is 220 mm. by 9 mm. ; this is, however, much contracted, so that it is unusually 

 thick. The average seems to be about 360 mm. by 7 mm. The worm is thus of 

 considerable length and stoutness. 



The anterior segments are quadriannulate ; the post-clitellar segments are 

 triannulate. 



Clitellum. — When fully developed the clitellum is dark brown, and extends 

 over segments (13) 14-19 (20). Of the five individuals collected in February only 

 two have the clitellum well developed ; while of the seven obtained in November 

 it is present in three, but in only two of these is it fully developed. Hence it appears 

 that there is no seasonal difference in regard to the maturity of the reproductive 

 organs, and that, like the European worms, the breeding season is not confined to 

 any particular period of the year. 



Internal Anatomy. 



The large gizzard is not wholly confined to the 6th segment, but the anterior 

 third lies in the 5th, the septum 5/6 being inserted round it at this point. The oeso- 

 phagus has thick longitudinally folded — i.e., " lamellate " — walls in segments 9-13 ; it 

 becomes much narrower in 14-19, but is somewhat dilated in each of the segments 

 14, 15, and 16, though no distinct glands exist. The intestine commences in the 

 20th. 



The nephridia are, in proportion to the diameter of the body, of very small 

 size, extending from chaeta a to c, lying close to the wall, as a fine slightly convoluted 

 tube, without a muscular bladder or duct. The tube can be traced through the 

 wall at the level of c. 



Of the three pairs of sperm-sacs, those in segments 9, 10, are long, narrow, and 

 far apart, while those in the 12th are close together. 



The simple form of the spermatheca which characterizes the species is exhibited 

 by all the individuals dissected. 



