576 



TREMATODA 



II. Without such process:- — 



Vitellaria from acetabulum to ovary in one 



msiss— 0 pi sth orchis . 

 Vitellaria divided into one mass in front of and 

 another behind the ovary- — Amfhimerus. 

 B. Testes branched 



Branches cover intestinal cgec a ventrally- — Clonorchis . 

 Type genus,—Opisthorchis R. Blanchard, 184- . 



OpisthorchisR. Blanchard, 1845. 



Definition. — Opisthorchiinae with long flattened body and some- 

 what pointed anterior extremity, suckers small, intestinal caeca 

 unbranched, yolk glands situate laterally and not extending beyond 

 the ventral sucker in front, testes in the posterior part of the body, 

 one behind the other. 



Type Species. — Opisthorchis felineus Rivolta, 1885. 



Classification. — The species of this genus are separated from 

 one another with great difficulty. 



The following are found in man: Opisthorchis felineus Rivolta, 

 iS8^; 0 pi sth or chts viverrini Voirier, 1866. 



These two species are distinguished as follows :- — 



A. Cuticle without spines^ — Felineus. 



B. Cuticle with minute spines — Viverrim. 



Opisthorchis felineus Rivolta, 1885. 



Synonyms.- — Distoma conus Gurlt, 1831, nec Creplin, 1825; D. 

 lanceolatum v. Siebold, 1836, nec Mehlis, 1825; D. sihiricum 

 Winogradoff, 1892; D. tenuicolle Miihl, 1896, p.p. j 



Definition. — Opisthorchis with cuticle without spines. 



Remarks. — Opisthorchis felineus lives in the gall-bladder and 

 bile-ducts of the domestic cat, and is also found in dogs in Europe. 

 The North American species is different (0. pseudo-felineus). 



In human beings it is apparently a common parasite in Siberia, 

 where it was first found by Winogradoff in Tomsk. 



Morphology. — It is reddish-yellow in colour, with a conical neck at the 

 level of the ventral sucker, marked by a shallow constriction. 



The length is from 8 to 11 millimetres and the breadth i'5 to 2 millimetres. 

 The testes lie in the posterior part of the body, one behind the other. The yolk 

 glands are situate on either side of the middle third of the body, beginning 

 behind the ventral sucker and terminating about the level of the ovary. 



The genital pore is close in front of the ventral sucker. 



The eggs are oval, with a well-defined operculum (30 by 11 ^). 



Life-History. — ^The parasites live in the bile-duct, and the eggs, 

 containing a ciliated miracidium, escape in the faeces. Complete 

 development[|is not known, but cercaria have been found in fish 

 which infect men and cats. 



Pathogenicity." — It causes inflammation, dilatation of the bile- 

 ducts in man, with atrophy of the liver substance, ascites, and 

 icterus. 



\ 



