are arranged into two layers, Diclybothrium armatum Leuckart (Fig. 90). 



The testes are well- delineated from the surrounding parenchyma 

 by a special connective tissue membrane. Sperm of monogenetic trematodes 

 arc usually thread-like and relatively long. 



Fig. 86. Cyclobothrium sessilis 



(Goto), adult worm. (According to 

 Goto, 1894). 



Fig. 87. Diclidophora poUachi 

 (Beneden and Hesse), adult worm. 

 (According to Braun, 1889-1893, 

 somewhat simplified). 



Seminal ducts are represented by efferent ducts (vasa efferentia) 

 and by a seminal duct (vas deferens), 

 canals 



The comparatively short little efferent 



which unite in pairs and then merge into one more or less long 

 seminal duct emanate from the testes. Goto (Goto 1894) indicated, however, 

 that among the highest Monogenoidea he did not see any efferent ducts and 

 supposes that the sperm pass from one testis to another by a system of 

 lacunae of parenchymatous origin. Among the species with a single testis, 

 the duct which emerges from it is designated as a seminal duct. It is 

 usually more or less powerfully twisted (serpentine, and often coiled as well, nobis ) 

 and starts from the testis at the ventral side of the body or in the middle of its 

 thickness and quickly rising to its dorsal surface, goes to the anterior end of the body p. 



61 



55 



