Mr. F. E. Beddard. On the [June 18, 



xterior by a very minute orifice. Although the orifice is so small its 

 presence is readily detected by the alteration in the character of the 

 epidermic cells ; the large, oval, glandular cells entirely disappear, 

 and the narrow columnar cells become more closely packed together, 

 and bend over towards each other on either side of the orifice, pre- 

 cisely as at the points where the setae protrude on to the exterior of 

 the body. The whole of the nephridium appears to be composed of a 

 variously coiled tubule consisting of rows of cells placed end to end 

 and perforated by the duct, as Claparede has described in Lumbricus ; 

 in the present species, however, unlike what is found in Lumbricus, the 

 terminal portion of the nephridium does not diif er at all from the rest, 

 except at the extreme distal end, where it appears that the lumen 

 ceases to be intracellular. This section of the tubule, which is very 

 slightly wider than the rest, is surrounded by a flattened epithelium 

 consisting of very small cells, and appears to be lined by a continua- 

 tion of the chitinous cuticle which covers the exterior of the body ; 

 this last fact, however, I am unable to state with certainty, though it 

 is probable for other reasons. I have observed the appearances 

 described above in a very large number of sections taken from dif- 

 ferent regions of the body. 



I propose at some future time to publish a fuller description, ac- 

 companied by figures, of these facts, which have some bearing upon the 

 morphology of the Annelida. 



It was supposed for a long time that only a single pair of nephridia 

 were to be found in each segment of the segmented worms. 

 Dr. Eisig,* however, found that in certain Polychaetous Annelids 

 belonging to the family Capitellidae, there were frequently four, five, 

 or even six pairs of nephridia in many of the segments of the body, 

 and that the number of pairs increased from before backwards. In 

 the present paper I have been able to extend Dr. Eisig's discovery 

 to the Oligochaeta, though the relation between the disposition of 

 the nephridia in the two groups is not at all a close one. 



In the Capitellidae the nephridia of each segment are deposed in 

 an oblique line passing from near the ventral parapodium of each 

 side to near the nerve cord ; their orifices, which, as in most Poly- 

 chaeta, are placed upon the summit of a tubercule, are grouped 

 together in an irregular fashion near to the parapodium ; moreover, 

 the young Capitellidae possess a larval series of nephridia — one to each 

 segment — which are replaced by the nephridia of the adult. It is, 

 therefore, a matter of great difficulty to institute a strict comparison 

 between the nephridia of the adult Capitellidae and those of Acantho- 

 drilus ; I can only call attention to the general fact that the Oligo- 

 cholia, like the Poli/chwta, may possess more than a single pair of 

 nephridia in each segment. 



* « Mitth. Zool. Stat. Neapel," Bd. i. 



