HUMAN LIVER FLUKES 



225 



of Shanghai. It is also found in the liver ducts of cats, hogs, 

 and probably other flesh-eating animals. It is from one-half to 

 three-quarters of an inch in length, and nearly four times as long 

 as wide. The ventral sucker is very small, and is situated on the 

 anterior third of the body. Some authors believe that a small 

 variety of this fluke found in Japan constitutes another species, 

 C. endemicus, but this view is assailed by recent investigations. 

 In Europe there occurs 

 a species, Opisthorchis 

 felineus (Fig. 75A), 

 which is very common 

 in domestic cats and 

 dogs and is by no means 

 uncommon in man; 

 there is one record of its 

 having been found in 

 eight or nine out of 124 

 post mortem examina- 

 tions in Siberia. A very 

 closely related species, 

 0. pseudofelineus (Fig. 

 75B), has been found in 

 cats and coyotes in the 

 central parts of the 

 United States. From 

 its similarity to the Old 

 World species it would 

 not be surprising to find 

 it occasionally parasitic 

 in man. 



The European species, 

 Opisthorchis felineus, is 

 usually a little less than 

 half an inch in length, and shaped very much like Clonorchis 

 sinensis. The American 0. pseudofelineus is somewhat longer 

 and slenderer than the European species. Another species of 

 the same genus, 0. noverca, occurs commonly in pariah dogs 

 in India, and occasionally in man. It differs from the Euro- 

 pean species chiefly in having the skin thickly beset with 

 spines. 



Fig. 75. A, Cat fluke, Opisthorchis felineus; 

 B, American cat fluke, O. pseudofelineus. Abbre- 

 viations as in Fig. 74. X about 5. (A, after 

 Stiles and Hassall; B, after Stiles.) 



