102 Transactions. — Zoology. 



wards dorsally (when the pharynx is retracted) to about the 

 22nd annulus, and then turns backwards to open into the 

 large thin-walled crop. The crop gives off six pairs of lateral 

 diverticula, increasing in size from in front backwards, the 

 1st pair being very small and lying at the sides of the 

 pharynx, while the 6th pair are large, sacculated on the outer 

 sides, and turn backwards so as to run almost longitudinally 

 to the level of the posterior sucker. The lateral diverticula of 

 the crop spring from the median portion opposite to annuli 

 25, 27, 29, 31, 33, and 35. Following the crop there comes a 

 curious sacculated portion of the alimentary canal, which we 

 propose to consider as the stomach, and which consists of 

 a median portion giving off four pairs of crowded lateral 

 diverticula opposite to annuli 36, 37, 38, and 39. Then follows 

 the intestine, the front half of which is greatly dilated to form 

 a pear-shaped sac, tapering off behind into a narrow portion, 

 which opens posteriorly at the anus. 



Nervous System. — The cerebral ganglia lie above the ali- 

 mentary canal about opposite to the 13th annulus. The nerve- 

 collar runs round the anterior portion of the pharynx and 

 connects the cerebral with the subcesophageal ganglia. The 

 suboesophageal ganglia and the three succeeding pairs of the 

 ventral chain lie in front of the male genital aperture. The 

 5th pair (counting the subcesophageal as the first of the chain) 

 lies immediately behind the male aperture, opposite the 21st 

 annulus. The 6th to the 17th pair inclusive lie in alternate 

 annuli from the 23rd to the 45th. The remaining ganglia, 

 about six in number, are fused together, and extend from 

 about the 47th annulus into the posterior sucker. 



Circulatory Organs. — The arrangement of the vessels and 

 sinuses in the genus Clepsine has been very fully worked out 

 by Oka,* and we have not thought it worth while to investi- 

 gate it in detail in the species under discussion. 



Nephridia. — The nephridia seem to exhibit great pecu- 

 liarities, and we regret that owing to the difficulties of the 

 investigation we are unable to give a complete account of 

 them. We have found in sections seven funnels, with 

 corresponding capsules, on each side ; these lie opposite to 

 annuli 23, 25, 27, 29, 31, 33, and 35, and seem to agree closely 

 with the corresponding structures as figured by Oka.* We 

 have also found seven pairs of external openings in the 

 integument, but these are placed on annuli 31, 33, 35, 37, 39, 

 41, and 43. We do not doubt that these are the nephridial 

 apertures, but we have been unable to trace any connection 

 between them and the internal funnels, and it seems strange 

 that they should be so widely separated from the latter. 



* Loc, cit. 



