TREMATODA. 37 



has been occasionally observed in man, but its usual 

 habitat is in the biliary passages in the Ruminantia. 



As is implied by its name, it is of a lanceolate 

 shape, and it fiurther differs from the D. hepaticum in 

 the circumstance of the intestinal canal consisting of 

 two straight, non-ramified divisions. 



Distomum Heierophyes. 



In this species the body is oblong, and flattened, 

 smooth upon its under, and slightly convex upon its 

 upper, surface ; the integument is covered by small 

 spines, which are directed backwards ; the buccal 

 sucker is small and funnel-shaped, and situated near 

 the end of the body ; the ventral sucker is placed 

 slightly in front of the middle of the body, and is of 

 considerable size, being about twelve times larger 

 than the buccal sucker. 



This worm has been found, upon two occasions, 

 hj Bilharz, in the small intestines of children, where 

 they were very numerous. 



Distomum Hcematobium. 



In this species the two sexes are distinct, but the 

 male, which is much larger than the female, contains 

 the latter enclosed in a canalis gyncecophorm, so that 

 the D. hcematobium partakes, in some degree, of the 

 hermaphroditic condition of the other species which 

 constitute the genus Distomum. 



It has, as yet, only been observed in Egypt, In 

 man, it Hves in the portal vein and its tributaries, 

 and in the walls of the urinary bladder. 



