Dr. O^Bryen Bellingliam on Irish Entozoa. 427 



, „ _ . ^ , r Intestine of whiting-pollach (Merlangus 



19. Distoma scabrum. . . . | PoUachius). 



20. contortum *. . Gills of sun-fish {Orthagoriscus Mola). 



. - , f Intestine of sun-fish (Orthagoriscus 



21. nigroflavum\i^ Mola). 



Species dubice. 

 00 n- f / Small intestine of great black-backed gull (Larus 



' ' \ marinus). 



23. . . Small intestine of scoter (Oidemia nigra). 



24. J. Rectum and cseca of tame swan (^Cygnus Olor). 



nearly of the same diameter throughout ; the anterior pore is very 

 small, the ventral larger and prominent, the aperture circular ; pores 

 rather distant from one another. 



* In the month of July 1839, I found a large number of the 

 Distoma contortum on the gills of a fine specimen of the sun-fish 

 (^Orthagoriscus Mola), which is now in the collection of the Natural 

 History Society of Dublin. The longest measures 10 or 11 lines in 

 length ; colour white anteriorly, yellowish red posteriorly. The body 

 is cylindrical, its greatest diameter being immediately behind the 

 ventral pore, from which it gradually diminishes towards the caudal 

 extremity. All the specimens soon became curved after being re- 

 moved from the animal ; indeed it is from this circumstance that 

 Rudolphi gave the species its name. The anterior pore is small and 

 circular ; the ventral large and elliptical or circular ; in some this 

 organ is seated upon a peduncle fully the length of the neck. The 

 neck measures nearly 3 lines in the longest specimens ; it is convex 

 upon the dorsal, and concave upon the ventral surface ; it, as well as 

 the head, is armed, jiarticularly upon the convex surface, with a num- 

 ber of minute spines, which are not seen posterior to the ventral pore. 

 The ova are very small, exceedingly numerous, and of a yellow colour ; 

 they appear to be the cause of the colour in the posterior division of 

 the body. 



t In the intestinal canal of the same sun-fish, I found several spe- 

 cimens of a Distoma which has the characters of the Distoma nigro- 

 flaviim of Rudolphi, but I could not see the aculei upon the head or 

 neck. The longest sjjecimen measures an inch and a half; the majo- 

 rity are about three-quarters of an inch in length ; colour in one part 

 black, in another yellowish ; head white. The ventral pore is pedun- 

 culated, the peduncle being sometimes as long as the neck (which 

 gives this species a resemblance to the Distoma fur catum) . The body 

 is cylindi-ical, slender, nearly of the same diameter throughout ; the 

 integument flaccid. 



X This Distoma, of which I found many specimens in the caeca and 

 rectum of a swan {Cygnus Olor), is a very beautiful species, and does 

 not appear to have been previously described. It approaches most 

 closely to the Distoma echinatum of Rudolphi, but differs in several 



2F2 



