98 THE ROYAL SOCIETY OF CANADA 



1. Amphistomum subtriquetrum. Diagram to show arrangement 

 of parts; dorsal view. 



2. Outlines natural size. A. Dorsal view. B. Side view. C. 

 Ventral view. 



3. Terminal part of sperm ducts; dorsal view. 



4. Median longitudinal section. 



5. Sagittal section of posterior end, showing giant cells in position. 



6. Transverse section through middle of pharynx; to show diverti- 

 cula of pharynx. 



7. Transverse section through posterior region of pharynx; to 

 show genital opening. 



8. Transverse section through posterior sucker; to show excretory 

 opening. 



9. Transverse section of dermal layers, showing prolongations of 

 subcuticular cells to the base of the cuticle. 



10. Transverse section of dermal layers, showing attachment of 

 parenchyma muscles. 



11. Horizontal section showing net-work of subcuticular cells below 

 the cuticle and circular muscles. 



12. Diagram to show various positions in which giant cells were 

 found. 



13. Normal giant cell (from the posterior sucker). 



14. 15. Giant cells with irregular nuclei (from the pharynx). 



