PLATE I. 



The following abbreviations retain the same significance throughout the present and 

 succeedingr Plates : — 



71. Nucleus or endoplast. 

 cv. Contractile vesicle. 

 f. Flagellum. 



cl. Collar. 

 o. Oral aperture. 

 an. Anal aperture. 



Where the figures are borrowed from another authority, the name of such authority is 

 bracketed ; where no bracketed name appears the figures are derived from the author's 

 original investigation. 



