224 S. J. JOHNSTON. 



anterior edge of the ventral sucker. The cirrus sac is welt 

 developed and entirely surrounds the much coiled vesicula 

 seminalis. Its position, relative to the ventral sucker, is 

 more posterior than in the other species of Lypersomum y 

 lying as it does almost entirely behind the anterior edge of 

 the ventral sucker, only reaching in front of it where it 

 passes forwards to reach the genital opening. The testes, 

 which lie close together, one behind the other, are separated 

 from the ventral sucker by a couple of coils of the uterus. 

 They are almost cubical in form, smooth edged and very 

 large, stretching right across the body, only leaving a small 

 amount of room for a coil of the uterus to pass on their 

 dorsal aspect. They are approximately equal in size, 0*35 

 x 0*27 mm. 



The ovary, which lies close behind the posterior testis, is 

 much smaller, measuring 0*194 x 0*116 mm. It is oval in 

 form and has its long axis -transversely placed. Posterior 

 to the ovary and in the dorsal region of the body, the 

 receptaculum seminis and gland of Mehlis or ''shell-gland" 

 are found. The yolk glands consist of a few (16 to 18) large 

 oval follicles measuring 0*08 x 0'07 mm. They are arranged 

 roughly in two rows and extend back wards from the posterior 

 aspect of the ovary for a distance of rather more than half 

 a millimetre. The uterus is very extensive, and in whole 

 mounts serves to hide the other organs a good deal. In a 

 number of closely packed coils it extends backwards to the 

 extreme posterior end of the body. From this point it runs 

 forwards in much looser coils on the ventral aspect of the 

 body as far as the posterior testis, where it passes to the 

 posterior side by making a coil between the ovary and the 

 testis. It partly separates the testes by a short coil and 

 throws two thick coils in between the anterior testis and 

 the cirrus sac. 



The eggs, especially those in the distal or ascending coils 

 of the uterus, are very dark brown in colour, oval in shape, 



