Dr. F. E. Beddard on the Genus Trichodrilus. 231 



nephridium may also occupy three segments, but considers 

 that he is here recording an abnormality*. Furthermore, 

 both Vejdovsky and Benham find in the genera Phreatothrix 

 and Stylodrilus a similar state of affairs in the second pair of 

 nephridia which traverse segments xiil.-XV. or (Phreatothrix) 

 Xiv.-xxi. I am not quite certain how far I can agree with 

 those authors from my examination of my species of Tricho- 

 drilus. The nephridial tubules in segments XII. &c. un- 

 doubtedly come into very close contact at the intersegmental 

 septa ; but I should not like to allege positively that they 

 form part of one nephridium extending through these segments. 

 In Vejdovsky's figure of the two first nephridia of Phreato- 

 thrix f the complex nephridia, if they are really formed by 

 fusion of the pairs belonging to the several segments through 

 which they pass, are represented as very simple in character; 

 they consist of simply two tubes running side by side. This 

 simplicity is also to be seen in Stylodrilus. In my species, 

 on the other hand, the coils of the nephridium are much more 

 numerous, and a considerable thickness of nephridial " tissue " 

 is thus to be seen in each segment. I take it that there is 

 here a resemblance to Teleuscolex korotnewi as seen by 

 Michaelsen J . 



As to the reproductive organs, none of the specimens 

 appeared to be fully mature § when examined with a hand- 

 lens. The clitellum could not be detected, and the only 

 external sign of maturity was the whitish appearance of the 

 two or three segments in a region just posterior to the male 

 pores, and which seems to be due to ripe ova. I therefore 

 did not preserve many examples for the elucidation of these 

 organs, but studied them in the living condition for the sake 

 of other organs, after which they were not in a very fit state 

 for fixing and hardening. Fortunately, however, I kept three 

 examples, in all of which the sexual organs were quite well 

 developed, and, indeed, tending perhaps towards degenera- 

 tion ; for while the thirteenth, fourteenth, and fifteenth seg- 

 ments contained a few ripe ova and the sperm-sacs were 

 obvious, the funnels of the sperm-ducts were, perhaps, rather 



* Claparede had already mentioned this fact in a worm erroneously sup- 

 posed to be Lumbriculus variegatus of Grube in his account of that worm 

 (in Mem. Phys. Geneve, t. c). The genus, however, to which Clapavede's 

 observations referred is now named Claparedilla (to be merged in BytJio- 

 nomus?). 



t Syst. u. Morph. Olig. Taf. xi. fig. 18. 



% Bull. Ac. Imp. Sci. St. Petersb. 1901, p. 169. 



§ According to Ditlevsen (referred to later) Trichodrilus allobrogurn is 

 fully mature in July. This difference of season may be a valid distinction 

 from the present species. 



