18 ARTHUR E. SHIPLEY. 



extent Pontobdella amongst the Rhyncobdellidae, and amongst 

 the Gnathobdellidae, Hirudo and Nephelis, and I may as well say 

 at once that my researches on these forms confirm the results 

 ■which Bourne published in the year 1884 in his exhaustive paper, 

 " Contributions to the Anatomy of the Hirudinea\" 



The points to which I particularly directed my observation fall 

 under three heads. 



Firstly: Do the internal funnels really open, or end blindly, 

 and in what spaces do their internal ends lie ? For instance, are 

 there any such sacs as Sedgwick has described enclosing the 

 funnels of the nephridia of Peripatus? 



Secondly : the communication between the true blood spaces 

 and the sinuses, the nature of the fluid found in these spaces, and 

 the circulation of the blood. 



Thirdly : the embryological origin of the sinuses. With re- 

 gard to tliis last I have been unable to make any investigation, 

 but a certain amount of information on this subject is found in the 

 writings of Nusbaum, Whitmann, and others. 



With regard firstly to the nephridial funnels of Clepsine, I can 

 fully confirm Bourne's statements. The funnel is usually com- 

 posed of two cells, but in some cases I have seen three nuclei 

 indicating the presence of three cells in the funnel ; these surround 

 a lumen ; on one side this lumen is continuous with the sinus, and 

 on the other hand with a sac. The lumen of the funnel is lined 

 with long cilia. Bourne's figure of this structure is rather dia- 

 grammatic ; the lumen of the funnel is occluded ; but he definitely 

 states that it opens, and in some of my preparations the coagulated 

 mass of fluid in the sinus is joined to a similar coagulum in the 

 sac mentioned above, by a strand of, coagulated matter which in 

 all respects resembles blood. The sac is usually full of coagulated 

 fluid with small corpuscles scattered in it. In one nephridium 

 there were two funnels, each opening into the sac ; and again, 

 I once saw a bunch of three or four funnels connected with the 

 single sac of a nephridium.. 



The internal end of the nephridium of Hirudo does not open, 



' Quarterly Journal of Microscopical Science, Vol. xxiv. p. 419. 



