Benham and Cameron. — Xephridia of Perieodrilus. 197 



The various loops of tubules are so extended that under a No. 8 diasect- 

 ing-lens of Leitz they appear to be independent of one another. They 

 are variously and irregularly arranged from segment to segment (c/. fig. 6). 

 Though usually concentrated near the nerve-cord, there is frequently a 

 Second bunch, or it may be only two or three loops, farther away ; and 

 in other cases the loops are more evenly distributed along the body-wall. 

 The coil is, however, usually limited to the lower half of the body. 



In the segments immediately following the clitellum the nephridial loops 

 are larger and more closely packed (fig. 7). 



Fig. 7. — Perieodrilus montanus. The nephridium, distinctly meganephric, of one 

 side of a segment just behind the clitelhim. 



A very fine duct, overlooked at first, passes upwards to penetrate the 

 body-wall at about the level of the 12th or 13th chaeta, and there is no 

 bladder. 



A funnel was detected, but owing to the poor state of preservation of the 

 tissue and the rather imperfect condition of the Sections we are unable to 

 figure it or do more than note its existence. 



We have not observed any branching of the narrow duct in the form 

 of processes looping round the other ducts of the fold ; nor are there 

 any blood-capillaries having the characteristic arrangement observed in 

 P. ricardi. 



The most prominent feature of P. montanus in preserved specimens is 

 the elaborate investment of blood-vessels which ramify over all the folds, 

 forming a closely covering network. This makes the nephridium an ex- 

 tremely beautiful object when viewed through the microscope, as each 

 capillary shines out clearly in the transparent folds, especially when 

 glycerine has been added to the preparation. 



List op Papers referred to in the Text. 



1. Benham. (Microchaeta.) Quart. Journ. Micro. Sci., vol. 26, 1886, 



p. 267. 



2. Benham. " Notes on Two Acanthodriloid Earthworms from New Zea- 



land." Quart. Journ. Micro. Sci., vol. 33, 1892, p. 294. 



3. Benham. " On the Old and some New Species of Earthworms belong- 



ing to the Geniis Plagiochaeta." Trans. N.Z. Inst., vol. 35, 1902, 

 p. 277. 



4. Benham. ' On some Edible and other New Species of Earthworms 



from the North Island of New Zealand." Proc. Zool. Soc, 1904, 

 vol. 2, p. 220. 



5. Benham. " Report on Oligochaeta of the Subantarctic Islands of New 



Zealand." Subant. Islds. N.Z., 1909, p. 251. 



