DICROCCELIUM DENDRITICUM 581 



History. — Bucholz appears to have been the first to discover 

 these worms in the gall-bladder in Weimar, and, later, Chabert in 

 the intestines of a girl in France, and Kiichner in Weimar. Since 

 then they have been noted in Italy and Egypt. They are found in 

 the bile-ducts of herbivorous and omnivorous animals in Europe, 

 North Africa, Asia, and North and South America. 



Morphology. — Dicroccelium dendriticum is a small trematode, measuring 

 8 to 10 millimetres in length by i'5 to 2'5 millimetres in breadth. It is pointed 

 in front and narrow behind, so that the widest point is just behind the yolk 

 glands. Cuticle is smooth; the oral sucker is terminal, and about the same 

 size as the ventral (0-5 to o-6 millimetre). The intestine bifurcates just in 

 front of the genital pore, which is situate in the median line in front of the 

 ventral sucker, behind which the two testes lie, from which the vasa deferentia 

 run forwards to form a cirrus lying in a cirrus sac. 



The ovary lies behind the posterior testis ; there is a receptaculum seniinis 

 and a Laurer's canal. The yolk glands lie in the lateral portion of the middle 

 fifth of the body, the posterior portion of which is filled up by the large coiled 

 uterus. The eggs are thick-shelled, and yellowish to brown in colour, with a 

 length of 38 to 45 and a breadth of 22 to 30 ^. 



Life-History.— Not known, but suspicion rests on Planorbis mar- 

 ginatus and land-snails. 



Pathogenicity. — No special symptoms. 



FAMILY ECHINOSTOMID^ Looss, 1902. 



Definition.- — -Fascioloidea, hermaphroditic, with a fold or collar 

 bearing a row or rows of pointed spines on the dorsal and lateral 

 aspects of the oral sucker. The rows of spines are continued laterally 

 on to the ventral corners, and the number of spines is constant for 

 each species. The corner spines are large or specialized. 



Classification. — The family is divided into two subfamilies as 

 follows : — 



A. Cirrus sac does not reach beyond acetabulum. Without 



strong rosethorn hooks — -Echinostomince. 



B. Cirrus sac reaches beyond acetabulum. With strong rose- 



thorn hooks — HimasthlincB . 



Subfamily Echinostomin^ Looss, 1S99. 



Definition. — As above. 



Type Genus. — Echinostoma Rudolphi, 1809. 



Classification. — E. malayanum Leiper, 1911, has been placed by 

 Odhner in the genus Euparyphium Odhner, so that it now becomes 

 Euparyphium malayanum, as, according to Leiper, it is probably 

 the same as Artyfechinostomum sufrartyfex Lane, 1915, which Lane 

 found in a girl of eight years of age on the Ragnik Tea Estate in 

 Assam. In 1916 Stephens pointed out that Lane's genus did not 

 possess the strong rosethorn hooks of the Himasthlinae. In 191 7 

 Lane pointed out that as Odhner's principal character of the 

 Echinostominae was that the cirrus sac usually reaches to the centre 



