TYPES OF SPECIES OF CESTODA KREFFT. 35 



The vagina extends inwards from the female pore, its main 

 mass lying in front of and somewhat ventrally to the cirrus sac. 

 Though its opening is narrow, the duct soon becomes widened to 

 act as a reueptaculum seminis. As it passes below the sac just 

 in front of the testes which lie on the right hand (i.e. the pore- 

 bearing) side, it again becomes narrowed and eventually reaches 

 the middle of the segment where it comes into relation with the 

 other female ducts. 



The uterus develops dorsally to the ovary, but ventrally to the 

 male organs. It finally becomes a well-defined rounded or 

 rectangular sac fPl. vi., fig. 4), the only other portion of the 

 genitalia persisting at this time being the vagina and the cirrus 

 sac. As mentioned by Ransom, the anterior margin of the 

 uterus lies practically at the junction between the segment to 

 which it belongs, and the preceding one. The eggs are from 34 

 to 42/x in diameter, the oncosphere measuring from 23 to 26/a 

 by from 19 to 23/x, and its hooks 11/x. 



If the foregoing sketch be compared with Ransom's account, 

 it will be admitted that the parasites are specifically identical. 

 The finding of H. megalops in Australian Anatidse thus greatly 

 widens the range of this Cestode, as the host in question ranges 

 over Australia and New Guinea. This helminth has so far been 

 recorded (according to Fuhrmann's list) 75 from ten species of 

 Anseriform birds ranging over Europe, North Africa, North 

 and South America and now from Australia. 



™ Fuhrmann— Zool. Jahrb., Suppl. Bd., x., Heft 1, 1903, pp. 149-158. 



