BY E. J. GODDARD. 775 



transverse sections one would be inclined to regard the nephridia 

 of segments vii.-x., as being in the form of one much-coiled, 

 continuous tube as is found to be the condition of the pregenital 

 nephridia in species of Phreodrilus. On examining longitudinal 

 sections, however, it is found that each of these segments has a 

 pair of nephridia quite distinct from those in the segments 

 anterior and posterior to it; but the nephridia on each side 

 occupy nearly the whole distance between the anterior and 

 posterior septa of a segment, so that the coils of any one nephri- 

 dium on each side lie in close proximity to the funnel-region of 

 the nephridium which passes through the septum from the next 

 posterior segment. The almost unavoidable obliquity of trans- 

 verse sections (however slight it may be) is enough to show, in 

 one section, traces of the nephridia of at least two adjacent 

 segments, but there is certainly no continuity as regards the 

 nephridia of segments vii.-x. 



In his description of Phreodriloides, Benham remarks of the 

 nephridia that " they seem to be asymmetrically disposed, for the 

 first organ lies on the left side of segment vi. Those of the 

 following segments are also confined to the left side; that in 

 segment x. is on the right side; and further back I see only one 

 in a segment" (I.e. p. 262). 



This asymmetry in Phreodriloides finds its parallel in Astacop- 

 sidrilus in a corresponding complete disappearance of the rudi- 

 mentary spermathecal duct of one side, and not in the disappear- 

 ance of the nephridia of any one side. 



It is rather an interesting fact that the pregenital nephridia in 

 Phreodriloides Benham, and Astacopsidrilus mihi — two genera 

 belonging to New South Wales — are apparently not united to 

 form a continuous tube, whereas such is the case in Phreodrilus 

 albus, P. Kerguelenensis, P. niger, and probably also, Benham 

 thinks, in P. lacustris. 



Again, Phreodriloides shows an asymmetry in regard to the 

 pregenital nephridia, and these are quite absent, apparently, in 

 Phreodrilus sublerraneus. Astacopsidrilus agrees with Phreo- 

 drilus Kerguelenensis in that the pregenital nephridia occupy 



