TREMATODES OF AUSTRALIAN BIRDS. 197 



1 ram. behind the anterior end and projects prominently on 

 the surface. It is fairly globular and has a diameter of 

 0*347 mm. 



The ratio of the oral to the ventral sucker is 1 : 4. The 

 oesophagus leading back from the small pharynx (0*116 X 

 0*106 mm.) bifurcates just in front of the anterior end of 

 the cirrus sac, and the two intestinal limbs run back to the 

 posterior end of the body. 



The tubular excretory vesicle divides into two main 

 branches immediately behind the posterior testis. 



The genital pore lies in the middle line of the ventral 

 surface just in front of the anterior border of the ventral 

 sucker. The cirrus sac, which is nearly filled by the volu- 

 minous vesicula seminalis projects far behind the ventral 

 sucker towards the posterior end. 



The gonads are situated very far back and lie in the 

 posterior body-fifth. The testes are large, somewhat 

 irregular, elliptical bodies lying close together and one 

 behind the other in the middle line. In one specimen the 

 posterior 0*776 x 0*33 mm., was a little longer than the 

 anterior 0*698 x 0*31 mm., but in two others they were 

 oqual in size and measured 1*028 x 0*388 mm. The ovary 

 is oval, 0*252 x 0*194 mm., with the long axis transversely 

 placed. It lies in the middle line a short distance in front 

 of the testes. A very large shell-gland, which is traversed 

 by the transverse yolk-ducts, occupies the space between 

 the ovary and testis. The yolk-glands, which consist of 

 large oval follicles, 0*063-0*074 mm. long by 0*043 mm. 

 wide, occupy two lateral fields stretching from the middle 

 of the body to the posterior end. These fields are inter- 

 rupted at three places, at the level of the ovary and each 

 of the testes, the intervals being bridged over by the longi- 

 tudinal yolk-ducts only. 



The uterus is extremely long and is thrown into numerous 

 transverse coils. It contains numerous eggs. The eggs 



