232 THE ANIMAL PARASITES OF MAN 



Family. Opisthorchiidae, Braun, 1901, emend, auctor. 



Ovary in front of testes. Small to medium flukes, very transparent, tapering 

 anteriorly. Vitellaria moderately developed not extending in front of sucker. 

 Cirrus absent. Seminal vesicle a twisted tube free in parenchyma. Testes near 

 bind end one behind the other, lobed or branched, but not dendritically. Excretory 

 bladder Y-shaped, the two limbs short, the stem S-shaped passing between the 

 testes. Receptaculum seminis well developed. Laurer's canal present. Uterine 

 coils transverse, numerous. Eggs small. 



Sub-family. Opisthorchiinse, Looss, 1899, emend, auctor. 



OpisthorchiidcE in which the excretory pore is terminal. Excretory bladder long, 

 dorsal to testes. Uterine coils not overlapping gut forks. Genera : Opisthorchis^ 

 Paropisthorchis, Clonorchis, Amphimerus, etc. 



Sub-family. Metorchiinae, Lube, 1909. 



Opisthorchiidce in which the excretory pore is ventral. Excretory bladder short, 

 ventral to testes. Uterine coils partly overlapping gut forks and extend anteriorly 

 beyond the sucker. Vitellaria compressed on the sides of the body. Genus : Metorchis. 



Family. Dicrocoeliidae, Odlmer, 1910. 



Ovary behind testes. Testes behind the ventral sucker, between it and the ovary. 

 Body thin and transparent. Cirrus sac encloses the pars prostatica and seminal 

 vesicle. Skin smooth. Gut forks do not reach posterior end. Receptaculum seminis 

 and Laurer's canal present. Vitellaria, moderate, lateral in mid-body slightly over- 

 lapping the gut. Uterus with an ascending and descending branch and numerous 

 transverse coils extending to hind end. Eggs dark brown, 25 fj. to 60 /*. Excretory 

 bladder tubular in posterior third or half of body. Parasitic in bile-ducts of mammals 

 and birds. Genus : Dicroccelium. 



Family. Heterophyiidae, Odhner, 1914. 



Ovary in front of testes. Genital pore behind or on a level with ventral sucker. 

 Genital pore surrounded by a pseudo-sucker (i.e., its muscle is not sharply separated 

 from but blends with the body muscles). Cirrus sac absent, consequently vesicula 

 seminalis and pars prostatica lie free. Vagina and ejaculatory duct unite into a 

 common duct before opening. Small and very small forms. Body covered with 

 scales. Genera : Heterophyes, Metagonimus, etc. 



Family. Troglotremidae, Odhner, 1914. 



More or less flattened Distomes of compact form, 2 to 13 mm. long. Ventral 

 surface flat or somewhat hollowed, dorsal surface arched. Skin completely covered 

 with pointed spines. Musculature weakly developed also in the suckers in those 



