Dr. O'Bryen Bcllingliam on Irish Entozoa. 4-23 



after the specimens have been preserved in spirits of wine for 

 some time. Upon the whole, however, the relative size and shape 

 of the pores appear to be almost the only characters by which 

 many species can be distingnished from each other ; and if it were 

 understood that this character was to be taken from the animal 

 which had been preserved in spirits (not from the recent animal), 

 it would help to prevent confusion. 



A. Inermia. 

 a. Plana vel depressa. 

 Poro ventrali majore. 



1. Distoma hepaticum *. . Liver of sheep (Ovis Jries). 



2. tumidulum .. Intestine oi T[)i-pe-&sh (Syngnathus Jcus). 



( Small intestine of teal (^Anas Crecca). 



3. oxycephalum \ I Small intestine of shoveller {Anas Cly' 



\^ peata). 



4. fidvum .... Intestine of skate (Raia Batis). 



* The Distoma hepaticum has been longer known than any other 

 species of the genus ; under the name Fasciola hepatica it is men- 

 tioned by Pennant and Turton as a British species. It inhabits the 

 biliary ducts of the sheep, in which it is not at all uncommon, and 

 sometimes occurs in considerable numbers. It has been found also 

 in the ox, the horse, goat, hare and stag ; and is said to occur in the 

 human subject, but I am not aware of any well-authenticated case 

 in which it has been detected. It does not occur in healthy sheep ; 

 at least the liver of the animals in which it occurs have always a dis- 

 eased appearance, are irregular and knotted upon the surface, and the 

 biliary ducts are enlarged, sometimes to a considerable extent. It 

 accompanies the disease known under the name of the rot, and will 

 be always found in the liver of the animals which die of it. 



t On two occasions I found numerous specimens of the Distoma 

 oxycephalum in the small intestines of the common shoveller {Anas 

 Clypeatu) ; they are about 2 lines in length, colour white, body flat- 

 tened (not exactly linear, as Rudolphi states), half a line in width, 

 tapering gradually towards the posterior extremity, which is pellucid ; 

 the anterior extremity is very narrow ; the anterior pore is extremely 

 small, orbicular, and rather inferior than terminal ; the ventral pore 

 is very large in comparison, orbicular, and prominent with a tumid 

 margin. The ovaries occupy each side of the body posterior to the 

 ventral pore. 



The specimens of D. oxycephalum from the teal resemble those last 

 described, but the body is rather subcylindrical than flat ; they are 

 between 3 and 4 lines in length ; the ventral pore is large, seated near 

 the anterior pore, and the body has the greatest diameter at this part. 

 The posterior extremity is obtuse, and appears to have a very short 

 appendage projecting from it. 



