38 



DESCRIPTIONS OF FOUR DISTOMES. 



EXPLANATION OF PLATE IV. 

 All the figures except 3 and 7 were made with the aid of a camera lucida. 



ABBREVIATIONS. 



oes. 

 or. 

 phx. 

 po. exc. 

 po. gen. 

 prs. prost. 

 rep. sem. 

 rsv. vt. 

 sac. dr. 

 te. 

 ut. 



vsl. exc. 

 vsl. sem. 



(Esophagus. 



Mouth. 



Pharynx. 



Excretory pore. 



Genital pore. 



Pars prostatica. 



Receptaculum seminis. 



Yolk-reservoir. 



Cirrus-sac. 



Testis. 



Uterus. 



Excretory vesicle. 



Vesicula seminalis. 



PLATE IV. 



Fig. 1. Renifer ellipticus, ventral view. X30. 



Fig. 2. Renifer elongatus, dorsal view. X33. 



Fig. 3. Diagram showing the arrangement of the female genital organs of R. ellipticus. 



Fig. 4. Outline of a cross-section of R. elongatus just posterior to the testes. X78. 



Fig. 5. Renifer variabilis, dorsal view. X24. 



Fig. 6. Ostiolum formosum, ventral view. X14. 



Fig. 7. Diagram showing the arrangement of the female genital organs of 0. formosum. 



Fig' 8. Cross-section of the ventral body-wall of 0. formosum showing acetabulum. XlO. 



