36 
yitellaria moderately developed, occupying about the equatorial third of the body. 
Eggs oval, 27 to 30 by 15 to 17 //; dark brown, with sharply defined operculum; 
contain ciliated embryo at oviposition. Sporocyst, redia, circaria, and intermediate 
host undetermined. 
Figs. 51-58. — Eggs of Opisthorchis sinensis in different stages of development, as found in the uterus. 
Note the operculum at one end. Greatly enlarged. (After Katsurada, 1900, pi. 13. figs. 2-9.) 
Habitat. — Gall ducts, pancreatic ducts, duodenum, and stomach of man {Homo 
sajjiens) and cats {Felis catus domestica). 
Geographic distribution.— Asia; sporadic imported cases elsewhere. 
Several imported cases of this parasite have been found in the 
United States and Canada. In some of the Japanese cases that have 
J-P 
Figs. 59-60. — Free embryos (miracidia) of same. Greatly enlarged. (After Kat.surada, 1900, pi. 13, 
figs. 10-11.) 
been recorded several thousand parasites have been present, and while 
the hepatic ducts are more frequently affected, some cases are recorded 
of the presence of this fluke in the pancreatic ducts, in the duodenum, 
and in the stomach. See p. 8. 
