572 



TREMATODA 



diameter. The testes are elliptical and situate posteriorly. The 

 ejaculatory ducts open with the uterus into a genital sinus, which 

 opens into a pit at the front of the ventral sucker. 



The ovary is spherical, and lies in the middle of the posterior part 

 of the body. A receptaculum seminis and a Laurer's canal are 

 present. The vitellarian acini lie on each side in the posterior part 

 of the body. The uterus forms three to four transverse coils. 



Life-History.— The eggs are elliptical, 28 x i6 microns, double 

 contoured and yellowish brown, with an operculum, but no shoulder, 

 and a knob at the narrower end. 



Muto found cercaria in the liver of Melania libertina, in Kaishu, 

 Korea, where metagonimiasis is common. On breaking up the liver 

 in water, it was found that the cercaria became encysted under the 

 scales of uninfected goldfish kept in the water. Kittens fed with 

 these fish became infected in twelve to fifteen days. 



The cercariae also live in a trout, Plecoglossus altivelis, rarely in 

 other fish. Infection takes place by eating raw fish, and the period, 

 judging by dogs, is seven to sixteen days for the eggs to appear 

 in the faeces. 



Patliogenicity.— It causes chronic diarrhoea in man. 



FAMILY TROGLOTREMIDiF: Odhner, 1914. 



Definition.- — -Fascioloidea hermaphroditic, with ovary in front 

 of testes, genital pore just in front or just behind rim of 

 acetabulum, but not surrounded by a pseudo-sucker, and with the 

 cuticle completely covered with pointed spines. Vitellaria well 

 developed and for the most part dorsally situate. More or less 

 flattened worms 2-3 mm. in length, with extreme posterior end 

 prolonged into a small appendage, with ventral surface flat or some- 

 what hollowed, and dorsal surface vaulted. Musculature in forms 

 living in cysts poorly developed. Pharynx present. Gut diverti- 

 cula terminal e a short distance from the posterior end. Genital pore 

 immediately in front or immediately behind the rim of the aceta- 

 bulum in the middle line or slightly to the left. Cirrus usually 

 absent. Pars prostatica and seminal vesicle present. Testes 

 symmetrical. Ovary in front of the testes. Vitellaria well 

 developed. Uterus long and much coiled, with small eggs, or short 

 and kinked with large eggs. 



Remarks. — Odhner formulated this family in Zoologiska Bidrag 

 frah Uppsala in 1914 for Distomum acutum, in the frontal sinuses of 

 Mustela putoria ; D. gastrophilum from cysts in the pylorus of 

 Phoccena communis ; for Collyrich^m faba from Sylvia hortensis and 

 ior Paragonimus ringeri, etc. 



Type Species.— Troglotrema Odhner, 19 14. 



Genus Paragonimus Braun, 1899. 

 Definition.— TroglotremidcC with thick, oval, or broad, fusiform 

 bodies, almost circular on transverse section. Cuticle, with sac- 

 like spines. Suckers separated by half the length of the body. 



