The third group of attaching organs, that is of suckers, does 

 <not require a detailed description. 



The suckers are basically of one structural type differing from 

 each other in shape and size, and also by the presence of subdivisions 

 within themselves and as a rule various chitinous formations which are 

 derivatives of the lateral hooks. 



The number of suckers usually fluctuates from 2 to 8, and they 

 are located symnnetrically along the ventral surface of the attaching discs 

 (Figs. 22, 35, 36). 



31 



9»o fon _^Oiv*?'_rt^ Ao 



Fig. 36. Heteronchocotyle 

 hypoprioni Brooks, adult 

 worm, (According to Brooks, 

 1934). 



Fig. 37. Hexd'stoma grossum (Goto), 

 adult worm from the gills of Katsuwonus 

 vagans (Less.) from the region Nagasaki 

 (East China Sea). 



24 



