DICKOCCELIID^: 



265 



M.S. 



Ejaculatory duct opens with the uterus into a genital sinus, which, 

 together with the internal opening of the ventral sucker, opens into a 

 pit at the front of the ventral sucker. The opening of the genital sinus 

 and that of the ventral sucker are furnished with a complex muscular ap- 

 paratus. Ovary spherical, cr 12 to 0*13 mm. in diameter, lies in the middle 

 of the hind body. Receptaculum seminis and Laurer's canal present. 

 Vitellaria in the hind half of the body, consisting of about ten acini on 

 each side. Shell gland to the left of the 

 ovary. Uterus forms three to four trans- 

 verse coils. Eggs elliptical, double 

 contoured, yellowish-brown in colour. 

 There is no shoulder below the oper- 

 culum as in the eggs of CL sinensis. 

 At the rounder end there is a thicken- 

 ing or knob different from the spine- 

 like or hook-like process seen in Cl. 

 sinensis. Dimensions 28 yu, by 16 //,. 



Habitat. Mainly in upper or 

 middle portion of jejunum, rarely in 

 caecum. They penetrate deep into the 

 mucosa, but not into the submucosa, 

 and post mortem appear as a number 

 of small brown points. They fre- 

 quently occur in the solitary glands, 

 which they destroy. They cause 

 chronic catarrh of the gut. Parasitic 

 in man and mammals. 



Geographical D istribution. ] apan . 



Life- history. The cercarial stage 

 occurs in a trout (Plecoglosstis altivelis) 

 and seldom in Crassius sp. and Cypri- 

 nus sp. Infection takes place through 

 the eating of the fish raw. Seven to 

 sixteen days later eggs appear in the 

 fasces (of dog). 



Family. Dicrocoeliidae, Odhner, 1910. 

 Genus. Dicrocoelium, Dujardin. 



FIG. 165. Dicroccelium dendriticum, 

 Rud. V.s., ventral sucker ; Cb., cirrus 

 pouch; /., intestinal caeca; V.sc., vitel- 

 laria ; T., testicles; O., ovary; M.S., 

 oral sucker ; #., uterus. IS/ 1 * 



Dicrocoeliidce, 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. 



