336 AUSTRALIAN ENTOZOA, 



visible in sections, consisting of a very short main trunk opening 

 at the pore, which divides into several principal branches, the 

 ramifications of which become obscured in preserved specimens. 



The testes are two densely staining, elongated bodies, with a 

 bulbous, lobed, almost moniliform outline, situated just posterior 

 to the ovary and shell-gland, and lying one behind the other, 

 stretching obliquely across the median line. In a body length 

 divided into fourths they occupy the third quarter. The vasa 

 deferentia unite before reaching the ventral sucker, and the 

 common duct, running behind and slightly to the left of that 

 sucker, on a level with its anterior part, expands to form a 

 conspicuous vesicula seminalis, which, in its anterior part, twisting 

 on itself, leads into an ejaculatory duct, and through the cirrus 

 to the genital opening. The ovary is a conspicuous, subglobular, 

 fairly solid body, situated about the middle of the animal. From 

 it the oviduct runs back for a short distance; then, bending 

 through 180° it runs forwards almost parallel to its former course, 

 and on a level with the anterior edge of the ovary it expands into 

 the uterus. At the bend it receives the united duct of the yolk- 

 glands, and a little further forward the duct of the shell-gland 

 opens into it. The uterus extends to the posterior aspect of the 

 ventral sucker in about eight turns or coils, and there ends in the 

 vagina, which, skirting the left side of the ventral sucker and 

 vesicula seminalis, opens into the common genital chamber, 

 opposite the male aperture. The common genital chamber is 

 very small. The uterus of each of the specimens examined was 

 distended with eggs, which are elliptical in shape, the chitinous 

 egg-shells of the preserved specimens being straw-coloured. The 

 eggs of a specimen which was mounted, when fresh, in glycerine 

 measured 0'13x 0*069 mm. There is little or no appreciable 

 variation in size. The shell-gland is large, and situated behind 

 and to the left of the ovary. 



The yolk or vitelline glands consist of a large number of 

 rounded follicles extending from the ventral sucker to the 

 posterior end of the body. From their anterior boundary, as far 

 back as the first testis, they are confined to the lateral aspects of 



