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HtANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY 



muscles in the body. There are also muscles wliici] run 

 dorso-ventrally, connecting together the dorsal and 

 ventral body walls, and there are probably some longi- 

 tudinally arranged muscles, though these latter are not 

 very evident. When the animal dies the ventral sucker 

 usually forms a prominent projection on the ventral 

 surface, and the extremities are bent dorsally. This is 

 probably due to the relaxation of the system of muscles 

 surrounding the sucker, and to a contraction of longitu- 

 dinal connective tissue fibres in the dorsal body wall. 



The genital aperture is situated on the ventral 

 surface in the middle line, and immediately behind the 

 bifurcation of the intestine. It is not very evident in 

 cleared preparations and can be recognised usually by the 

 protruded cirrus. (Fig. 2,) 



Gen ita 

 CLiHum 



Cirrus iQc 



CProstate 

 and 



Fig. 2. Allocreadium labracis (Duj.). Part of median longitudinal 

 section through genital cloaca. 



The Male Organs (Fig. 3). 



There are two testes, nearly spherical in shape, but 

 with rather irregular outlines, and nearly equal in size. 

 They are situated nearly midway between the ventral 

 sucker and the posterior extremity of the body. They 

 lie one behind the other in the middle line. A vas 

 efferens takes origin from each, one vessel from the 



