Life-history.—The cercarial stage occurs in a trout (Plecoglossus altivelis) and seldom in Crassius sp. and Cyprinus sp. Infection takes place through the eating of the fish raw. Seven to sixteen days later eggs appear in the fæces (of dog).
Family. Dicrocœliidæ, Odhner, 1910.
Genus. Dicrocœlium, Dujardin.
Dicrocœliidæ, with leaf-shaped bodies, pointed posteriorly and anteriorly. Greatest width behind the mid-line. Vitellaria double. The testes smooth or indented, lying symmetrically or obliquely beside or behind the ventral sucker. The ovary approaches the median line behind one testis. Parasitic in the liver and gall-bladder (rarely in the intestine) of members of all classes of vertebrate animals—by preference in birds and mammals.
Dicrocœlium dendriticum, Rud., 1819.
Syn.: Dicrocœlium lanceatum, Stil. and Hass., 1896; Fasciola lanceolata, Rud., 1803 (nec Schrank, 1790); Distomum lanceolatum, Mehlis, 1825; Dicrocœlium lanceolatum, Dujardin, 1845.
Fig. 165.—Dicrocœlium dendriticum, Rud. V.s., ventral sucker; Cb., cirrus pouch; I., intestinal cæca; V.sc., vitellaria; T., testicles; O., ovary; M.s., oral sucker; Ut., uterus. 15/1.