172 Tra/tfiacf/uiis. 



resemblance to tliis species. Aside from these two poiiits tlie species under 

 consideration fits Quoy and Gaimard's description very well. Further 

 weight is added to the diagnosis by the fact that Mr. Oliver has found 

 this species very common at the locality where Quoy and Gaimard collected 

 it — viz., Bay of Islands. Shape, striking colour, and common occurrence at 

 the Bay of Islands and Hauraki Gulf leave little doubt. T think, that this 

 is Quoy and Gaimard's species. 



Art. XIX. — The Minute Structure of the Nephridiuui of the Earthworm 

 MaoridriluS rosae Beddarcl . 



By Gladys M. Cameron, M.8c. 



Communicated by Professor Benham. 



[Jifnd before the Otcigo Institute, -hd Octotjer. 1911.] 



Historical. 



The earliest account of the microscopic structure of an earthworm "s 

 nephridium of any value is that by Gegenbaur (19), in 1853, in which he 

 showed also that what had np to that time been regarded as an organ 

 of respiration is indeed one of excretion. This account of the nephridium 

 of Lumhricus stood alone till in 1886 Benham (8) gave some account of 

 the histology of the organ in an African worm, Microchaeta, though no 

 attempt was made to trace out the course of the tubule throughout its 

 windings; and although several zoologists about that time — Beddard, 

 iSpencer, Benham — contributed certain details as to structure in various 

 genera, we find no further effort to trace out the whole length of the canal 

 till in 1890 Goehlich reinvestigated that of Lumhricus (20). In the follow- 

 ing year Benham published (10) a still more detailed description of the 

 whole nephridium, stimulated thereto by certain statements of Goehlich 

 Avhich appeared to him to be at variance with Gegenbaur's accoiuit ; and 

 though he fell into one or two minor errors of misinterpretation* as to the 

 structure of the funnel, his account has been accepted and his figures copied 

 in several text-books. In that article Benham gives a summary of all that 

 was then known about the nephridium in various earthworms, and a list 

 of references to the papers on the organ. 



* Note by Professor BenJiavi. — It was stated that the margmal cells curved inwards 

 towards the centre and then became continuous with the reflected cells of the canal, 

 wWch I had termed " centrifugal gutter-cells." The same interpretation was given 

 by Schneider in his " Vergleichenden Histologic," p. 419. but Rosen has shown that this 

 is not the case. A re-examination of the preparation from which my figiire was drawn 

 shows me that Rosen's account is quite correct : there is a distinct gap between theso 

 two series of cells. Nor did I recognize the coelomic epithelium covering the lower 

 lip of the funnel. I confused it with the " debris " which collects at the mouth. 1 can 

 confirm Rosen (23) in the.se matters. 



