240 



S. VOSHIDA : 



The head is globular, measuring about 0.15 mm. across. The 

 rostellum is very small and likewise globular. The suckers, oval in 

 shape, are comparatively large, being 0.07 mm. long and 0.04 mm. 

 wide. A remarkable feature of the species lies in the fact that neither 

 the rostellum nor the suckers are armed with hooks. This negative 

 character was found to be constant with all the specimens examined, 

 and can not be due to loss. It seems the rostellum is too small and 

 weakly developed as to be able to bear any hook. I may mention 

 that Hymcnolcpis without hooks on rostellum is not new : I refer to 

 //. carioca (Magalhaîs) and H. -megalops (Nitzsch). 



The neck is subject to considerable variation as regards its 

 dimensions, according to the state of contraction of the worm. Generally 

 it is o. i-o.i5mm. long by a breadth of 0.08 mm.; sometimes it may 

 reach a length of 0.3 mm., the breadth decreasing at the same time 

 to about 0.05 mm. 



Genital pores unilateral. 



Male reproductive organs. — The testes, 3 in number to each 

 segment, are spherical, measuring 0.018--0.023 mm. in diameter. They 

 are most distinct in the younger segments in which the cirrus pouch 

 and seminal vesicle have not yet fully developed ; they are more or 

 less obliterated in segments of the middle as well as posterior parts, 

 in inverse proportion as the uterus enlarges. Two of the testes are 

 found side by side in the dorsal part of the aporose side, in transverse 

 line with the seminal vesicle and the cirrus pouch ; while the third 

 testis is situated ventral to seminal vesicle and the proximal end of 

 cirrus pouch (fig. 13, 



The seminal vesicle is a spherical body, measuring 0.025-0.03 mm. 

 in diameter and situated dorsally in the median line. In the posterior 

 segments containing ripe onchospheres the seminal vesicle is no longer 

 visible. 



The cirrus pouch is pyriform or club-shaped, situated in the dorsal 

 side. Length 0.06-0.07 mm - Greatest breadth in the proximal parts 



