56 Trmisactions of the Boyal Society of South Africa. 
The testes lie in the lateral flaps (3, Fig. 1), thus laterally to the 
vitellaria. In whole mounts it can easily be observed that each testis is 
divided into a pre-pharyngeal and a post-pharyngeal portion, thus 
resembling Mesostoma lingua ; but a reconstruction of serial sections 
shows that each of these two testicular portions is again subdivided 
irregularly ; Fig. 2 shows the pre-pharyngeal portion of the left testis with 
the vasa efferentia marked x. The vasa efferentia of each side join a 
longitudinal vas deferens, which, near the opening of the vitelline ducts 
Fig. 1. — Outline of body seen from dorsal surface with three sections through AA, 
BB, and CC. l = dorsal ridge; 2 = median portion of body, around gut; Bilateral flaps ; 
4 = sucker; 5 = pharynx and mouth; 6 = genital aperture. 
(12, Fig. 3), is connected to a vessel running forwards and meeting a 
similar vessel just before opening into the vesicula seminalis ; there is 
therefore no seminal duct, the two vasa deferentia only combining just as 
they enter the vesicula. The vesicula opens into the "granular" vesicle 
(3, Fig. 3), which contains the "granular" glands in it, the lumen for the 
passage of the seminal fluid being restricted to a narrow tube on the inner 
side. In the figure the penis is shown retracted within its sheath, so that 
