954 MR. H. R. MEHEA ON TWO NEW INDIAN 



yolky subsbance — a feature which distinguishes the Tubificidae 

 from the Naididse, in which the ovaries disappear early like the 

 testes. Each well-developed ovary measures about -088 mm. in 

 height and '095 mm. in breadth : it extends as far back as the 

 coelomic sac which lies in the hinder part of the segment. It is 

 composed of ova at various stages of maturity, somewhat loosely 

 arranged and not consolidated as in the Megadrili, and a large 

 mass of yolk. The yolk generally iills up a large space in the 

 centre of the ovary, while the ova lie all around it forming the 

 periphery ; in two cases, however, the yolk extended on the upper 

 border, and the ova were lying then on the anterior, ventral and 

 posterior margins. It seems probable that only the cells around 

 the periphery of the ovary develop into ova, and that the central 

 cells break up, lose their individuality and form the large amount 

 of yolk-matter. The developing oocytes, when of sufficiently 

 large size get discharged with a part of the yolk and find their 

 way into the ovisac, where they complete their further growth. 



There are no special blood-vessels for the ovary, or any part of 

 the genital apparatus ; the pei-i-visceral blood-vessels and the 

 dorsal vessel become much enlarged in the region of the body 

 containing them. 



The vas deferens lies in the 7th segment, and opens internally 

 by a large seminal funnel in the segment in front, piercing- 

 septum 6/7 ; it opens externally in a large ventral depression of 

 the body-wall — the spermiducal chamber. Each duct lies in two 

 segments and consists of the following parts : the seminal 

 funnel, the vas deferens proper, the atrium with the prostate 

 and the atrial duct, which is very long, much coiled and enclosed 

 in a thick coat of muscle fibres to form a spherical or ovoid 

 muscular or coelomic sac. 



The seminal funnels are situated in the 6th segment — i. e. the 

 segment in front of that in which the tube itself lies, near the 

 ventral parietes, projecting freely and lying in front of the lower 

 part of septum 6/7, below the opening of the sperm-sac (text- 

 fig. 4). Each funnel about 75 ft in height is cup-shaped with 

 everted lips ; in an advanced stage it is wide and shallow reaching 

 about 75 jji in breadth. It is lined by a single layer of columnar 

 ciliated cells of 20-28 ft height except near the margin of the 

 upper lip, where the height is somewhat less ; the cells are about 

 3-6 /x broad, are wider on their inner ciliated border and narrower, 

 appearing somewhat fibre-like at their outer end. The epithelial 

 cells contain large oval nuclei, 5-6 /.i in greatest diameter placed 

 about middle of their length ; the nuclei are somewhat smaller in 

 the lower marginal cells of the funnel. The cilia are fairly con- 

 spicuous. The peritoneal layer does not appear to be present 

 outside the funnel epithelium. The elongated sperm-heads of 

 ll-12"6fi length with the tails about four times in length lying 

 behind form a regularly arranged dense mass near the funnel 

 opening (text-fig. 4). The lower lip of the funnel lies near the 

 ventral parietes, about 32 fi distance from it. 



