BILHARZIA HiEMATOBIA. 197 



6. BlLHARZIA HJIMATOBIA. 



B. hcematohia, Cobbold. 



B. magna, Cobbold. 



Gyn(jeco])liorus hcematohius, Diesing. 



Thecosoma hoematobium, Moquin-Tandon. 



Distoma hcematobiu7n, Bilharz ; Kuclienmeister ; Moulinie ; etc. 



Distoma capense, J. Harley. 



Schistosoma hcematobium, Weinland. 



General and Specific Characters. — A trematode helmintli in which the male and 

 female reproductive organs occur in separate individuals ; the male being a cylindrical 

 vermiform worm, measuring only half an inch or rather more in length, whilst the 

 female is filiform, longer, and much narrower than the male, being about four-fifths of 

 an inch from head to tail ; in both, the oral and ventral suckers are placed near each 

 other at the front of the body ; in the male the suckers measuring j^", in the female 

 ^" in diameter ; in either, the reproductive orifice occurs immediately below the ventral 

 acetabulum. The comparatively short, thick, and flattened body of the male is tubercu- 

 lated and furnished with a f/yncscophoric canal, extending from a point a little below the 

 ventral sucker to the extremity of the tail ; this slit-like cavity being formed by the 

 narrowing and bending inwards of the lateral borders of the animal, the right side being 

 more or less completely overlapped by the left margin of the body ; caudal extremity 

 pointed ; intestine in the form of two simple blind canals. Female with a cylindrical 

 body measuring only s^-^ of an inch in thickness in front of the oral sucker ; lodged in 

 the gynfficophoric canal of the male during the copulatory act ; thickness of the body 

 below the ventral acetabulum being about sW', and at the lower part^V'; surface 

 almost smooth throughout ; intestinal canals reunited after a short separation to form 

 a broad, central, spirally twisted tube extending down the middle of the body ; vitel- 

 ligene and germigene canals combining to form a simple oviducal canal, which is con- 

 tinued into a simple uterine tube, finally opening near the lower margin of the ventral 

 sucker ; eggs pointed at one end, or by a projecting spine near the hinder pole. 



Most helmintliologists agree as to the propriety of placing tliis 

 remarkable trematode in a separate genus, but some dispute lias 

 arisen concerning the priority of the various titles which have been 

 proposed. The generic name here adopted is one which I applied to 

 a second species (as I then supposed) discovered by me six months 

 before Diesing communicated his " Revision der Myzelminthen" to 

 the Vienna Academy ; but I shall have no objection to employ the 

 title GyncBGophonis, proposed by him, if it be generally thought 

 more appropriate. Weinland has expressed to me his willingness 

 to abandon the title Schistosoma in favour of Bilharzia, wliich he 



