middle hooks is absent. The anterior end has weakly developed 

 cephalic glands. The eyes usually exist- -Z pairs. The digestive system 

 has a nriore or less well-developed buccal sucker, powerful pharynx 



and 2 intestinal trunks often merging with each other at the posterior end. 

 The intestinal trunks are simple or form external and internal branched 

 outgrowths and sometimes even commisures which in turn give off more 

 or less nunnerous outgrowths. The ovary is flask-shaped. The testes are 

 single or numerous, more seldom there are 2 of them. There is a ductus 

 genito-intestinalis. 



Parasites of Amphibia and Reptilia and,as an exception, of 

 aquatic man^mals. 



The suborder includes two families Polystomatidae (Carus) 

 Gamble and Sphyranuridae Poche. 



1. Family Polystomatidae (Carus, 1863) Gamble, 1896 



(Figs. 22, 50, 62, 71, 73, 74, 77, 82, 83, 85, 91, 

 100, 101, G, 126-130, 203-215, 288, 289) 



Polystomidae Carus, 1863. 



Polyopisthocotylinea, having middle and large sizes in the 

 adult state. The attaching disc bears 16 edge hooks, — 2—4 middle hooks 

 and 6 powerful suckers lying along the edge of the disc. Among adult worms 

 the cephalic glands are strongly reduced and replaced by a buccal sucker. 

 The eyes usually exist in the number of 2 pairs. The intestinal trunks are 

 either simple, without outgrowths, or they merge at the posterior end 

 either with outgrowths and also not merging at the posterior end or forming 

 numerous outgrowths, several commisures and merging at the posterior 

 end, with this a number of outgrowths departs from the place of the 

 anestomosis. The ovary is flask-shaped, the testes are single or numerous, 

 often follicular (see page 57), more rarely there are 2 testes. The uterus 

 is either absent and the ootype contains one egg or there is a well-developed 

 uterus. 



Parasites of Amphibia and Reptilia, as an exception- - 

 Hippopotamus . 



Type genus, Polystoma Zeder, 1800. 



In addition to the type genus into the composition of the family 

 enter Polystomoides, Ward, 1917; Parapolystoma Osaki, 1935; Diplorchis 

 Qsali, 1931; Polystomoidella , Price 1939; Neopolystoma Price, 1939; 

 Oculotrema Stunkard, 1924; Protopolystoma Bychowsky gen, nov. ^ and, 

 Eupolystoma Kam, 1850. 



479 



