402 FRANK E. BEDDARD. 



studied the anterior region of the body comprising the first 

 sixteen or seventeen segments. 



I have never observed any branching of the nephridial 

 tubules in the body wall like that which occurs in Acantho- 

 drilus (see fig. 1); but I am not prepared to deny that it 

 may occasionally happen. 



So far the nephridial system of Pe rich seta is closely 

 similar to that of Acanthodrilus, with only some small 

 differences in detail. 



An important point of difference is illustrated in fig. 7 ; in 

 this figure it will be seen that the nephridial network of 

 one segment is continuous through the septum with 

 that ofthe next. The nephridial system in fact differs from 

 that of any other earthworm, or indeed from that of any other 

 Annelid except Pontobdella (Bourne) (5), in that it forms a 

 continuous network uninterrupted by the inter- 

 segmental septa. Furthermore, there appears to be a 

 perfect continuity between the nephridial system of the right 

 and left halves of the body. The nephridial system of one 

 segment communicates with that of the neighbouring seg- 

 ments at numerous points ; there is no question here of a pair 

 of longitudinal ducts such as has been described recently in 

 Lanice conchilega (Lang (11), Cunningham 6). The 

 resemblance to Pontobdella is very striking, the only dif- 

 ference being that the external apertures in each segment are 

 numerous instead of beiug only a single pair. With regard 

 to internal apertures (funnels) I can say nothing. I have 

 been entirely unable to find any trace of them. 



The diagrams (fig. 13) illustrates what I believe to be the 

 arrangement of the nephridial network and the external pores 

 (o) in a few segments. I should say that I cannot pretend to 

 accuracy in the course of the tubules within the coelom. To 

 reconstruct from a series of sections the course of the com- 

 paratively simple nephridium of Lumbricus is a hard 

 enough task ; to map out accurately the extremely complicated 

 coils of the nephridial network of Perichseta is for me an 

 absolute impossibility. I can, however, assert most positively 



