1921.] Fauna of the Chilka Lake : Leeches. 665 



The glandular cells in the parenchyma are very weakly developed, and in no case 

 have I been able to demonstrate such large and round cells as are observable in the 

 following new species closely resembling this leech. 



The mouth lying nearly in the centre of the anterior sucker leads directly into 

 the pharyngeal sheath, which reaches behind somite VIII. In it lies the pharynx 

 which is of a short cylindrical shape and at the base receives the ducts of the salivary 

 glands widely distributed in the anterior parts of the body. The pharynx gives rise 

 posteriorly to a long passage, the oesophagus, which connects with the crop in somite 

 XIII. The crop is a distensible part of the digestive organ, extending backwards 

 nearly to the end of the trunk and ending blindly, and gives off a pair of slightly sub- 

 divided lateral pouches in each somite. At the end of somite XVIII the crop passes 

 dorsally into the stomach which bears four pairs of wide lateral pouches, lying within 

 somites XIX- XXI. The intestine is a narrow passage leading from the stomach 

 backwards to the anus which is situated dorsally just between somites XXVI and 

 XXVII. 



The vascular and coelomic systems are well developed, and appear to be 

 constructed on the same plan as in other species of Piscicola. The dorsal vessel 

 is single and lies in the dorsal sinus, forming some dilations in its course. In no 

 section have I been able to demonstrate the connection of the dorsal vessel with the 

 ventral. The dorsal and ventral sinuses give off metamerically arranged transverse 

 branches which communicate on each side with lateral sinuses and vesicles. 



The cephalic ganglionic mass lies for the most part in somite VI, consisting, 

 as is usual, of the fused ganglia of the first six somites. The acetabular mass is 

 composed of seven ganglia of the last seven somites forming the posterior sucker. 

 Between these masses there can be found twenty-one ganglia in the ventral chain, 

 each lying in the middle of the corresponding somite. 



The male genital aperture lies in somite XI, directly leading into the tubular 

 vestibulum, and the female aperture in somite XII. 



There exist six pairs of testes which are ovoid in shape and are situated inter- 

 metamerically on either side of the crop in somites xîiï- XVIII ■ Each testis gives rise 

 to a short vas efferens communicating with the vas deferens, which pursues a for- 

 wardly directed tortuous course and at the same time dilates into a thick-walled 

 glandular canal. In the region of the male genital aperture the canal nears the 

 median line and finally unites with its fellow of the opposite side to form a wide pas- 

 sage, the " prostate," which opens into the vestibulum. The prostate is lined with 

 an epithelium made up of high columnar cells closely packed, and is supplied with 

 the ducts of glandular cells forming a large accumulation. 



The ovaries are represented by a pair of simple sacs lying in somite XIII. Not 

 far behind the female genital aperture they unite into a short common duct which 

 makes its way to the exterior. 



Ventrally occupying somite XIII is found a swelling of the body-wall in some 

 specimens examined ; this may be regarded as representing a part of the clitellum. 



