IC)I5-] Fauna of the Chilka Lake : Oligochaeta. 143 



able by its greater width, in segment xv (in one specimen), xvi or perhaps xvii (in a 

 second). 



The salivary glands (fig. 1) are apparently represented by a pair of short club- 

 shaped backwardly directed evaginations of the pharynx ; these take origin from the 

 hinder part of the pharyngeal roof, behind the sucker-like epithelial plate, and are 

 situated one on each side near the middle line. 



The septal glands are situated on the anterior faces of septa 4/5, 5/6, and 6/7, 

 causing these to bulge backwards. Those of each pair are continuous dorsally over 

 the oesophagus; and each gland is continued forwards by an anteriorly projecting 

 lobe situated ventro-laterally to the oesophagus. In entire specimens the glands 

 appear to be in segments v, vi, and vii, and perhaps to be more than a single pair 

 per segment; but the appearances are explained by the backward bulging of the 

 septa, and the presence of the anterior lobes, as just described. 



The dorsal vessel is certainly distinct as far back as segment xv, — probably 

 further, as far as xvi, if not xvii. 



The nephridia have a short ante-septal portion , — perhaps a quarter the length of 

 the postseptal ; the post-septal portion is elongated, narrow, and gives off the duct 

 from its under surface at about one-third of its length from the posterior end ; the 

 duct is short, passes vertically downwards, and ends in front of the ventral 

 setae. 



The cerebral ganglion is in segment i ; its shape could not be determined. 



The description of the male genital organs (figs. 2, 3, 4) is most conveniently 

 begun with the sperm-sacs. These are two in number, quite distinct from each 

 other, of large size and ovoid shape (figs. 2, 3); they are continuous with and sus- 

 pended by septum 10/ri; they project forwards into segment x, and, still more, 

 backwards into xi, so that they occupy the whole length of the latter segment; their 

 walls are quite thin, but complete. Contained within this sac is a large mass of 

 sperm-morulae, in various stages of development; but, in the two specimens which 

 were sectioned, there were no wisps of fully developed spermatozoa. What is to be 

 considered as the testis is a mass of cells (figs. 2, 3), adherent to the inner face of 

 the sac-wall at its lower part, i.e. to the floor of the sac, approximately in the 

 region where septum 10/11 joins it. This mass of cells may project not inconsider- 

 ably into the interior of the sac; or it may constitute merely a flattened plate, 

 perhaps divided up into a number of smaller masses. The morulae within the sac are 

 evidently developed from cells which are proliferated from the cell-mass or cell- 

 plate; indeed there is a gradual transition from the one to the other. The funnel 

 (fig. 4) is in segment xi; it is two or three times as long as broad; it has the usual 

 cylindrical shape, but the cells of which it is composed have not the usual clear 

 mucous appearance in stained sections ; this might possibly be due to the specimens 

 being in a rather early stage of sexual maturity. The vas deferens is situated in 

 segment xii; it is long, thin, i6m in diameter, and coiled; fig. 4, sketched from an 

 entire specimen in cedar oil, will give an idea as to its disposition and course. The 

 penial body is a small hemispherical mass of cells round the termination of the vas 



