16. Distoma echinatum "^ .< 



426 Dr. O'Bryen Bellingliam on Irish Entosoa. 



'Small intestine of swan {Cygnus Olor). 

 Rectum of wild swan {Cygmis ferus) . 

 Small intestine of golden-eye (Clangula 



chrysophthalmos) . 

 Rectum and caeca of widgeon (Mareca 



Penelojye), 

 Small intestine and rectum of crested 



grebe and tippet grebe {Podiceps cris- 



tatus) . 



17. militare, . . . Rectum of curlew (Numenius arquata). 



rSmall intestine of golden eye {Clangula 

 ] chrysophthalmos) . 



TO • 7 J. ;' Small intestine of black-headed eruU CZ/G- 



18. ■ ■ sptnulosum J . < • i-r i \ t> v 



-^ j rus rtaiounaus). 



Small intestine of curlew (Numenius ar- 

 [^ quata). 



* The Distoma echinatum, from the small intestine of the golden- 

 eye (Clangula chrysophthalmos) , is flattened, nearly 3 lines in length ; 

 colour dirty white, particularly about the situation of the ovaries, 

 which occupy the sides of the body, and appear to contain nume- 

 rous ova. Immediately on being placed in water they became convex 

 on the dorsal surface, and concave ujion the abdominal surface. The 

 head is subreniform, armed with a ring of distinct spines ; neck rather 

 long, concave inferiorly ; anterior pore very small and terminal, 

 ventral large and prominent ; both orbicular. In one specimen, a 

 short and conical cirrhus projected a little anterior to the ventral 

 pore. 



The specimens of Distoma echinatum from the rectum of the wild 

 swan which I have found, are in some cases 6 or 7 lines in length, 

 in others not more than 2 lines ; the majority belong to the latter ; 

 and there are none of an intermediate length, though both apparently 

 belong to the same species. The body is more cylindrical than in 

 the specimens from the golden-eye ; the pores are distinct and cir- 

 cular, seated near each other, the ventral being the larger. The head 

 is small and armed with spines ; the neck is convex upon the dorsal, 

 and concave upon the abdominal surface. 



My specimens of Distoma echinatum from the rectum and cseca of 

 the widgeon have a greater length and transverse diameter than those 

 from which R,udolphi took his description ; the head is also smaller 

 in proportion to the body, and is armed with more numerous spines 

 than are represented in I3remser's figure of this species. 



t The Distoma spinulosum, from the golden-eye (Clangula chry- 

 sophthalmos), is little more than a line and a half in length ; colour 

 perfectly white ; flat and linear before being immersed in spirits of 

 wine, becoming rather cylindrical afterwards. The head is small, 

 armed with minute spines ; neck conical and long, about half the 

 width of the body, and one-third of its length. The body is pretty 



