594 Jnnd ^¥. Raff: 



Fig. 1. — Nyctotherus cord i form is, showing macro-nuclens. 



Fig. 2. — -Same, stained with Heidenhain's iron haematoxylin, 

 showing peculiar backwardly projecting fiagellum at end 

 of oral groove. Drawn with the camera lucida. 



Fig. 3. — Same, undergoing transverse division, showing macro- 

 nucleus dividing. Drawn with the camera lucida. 



Fig. 4r. — Same, drawn with the camera lucida to show the rela- 

 tive sizes of the giant form, Fig. la, and the normal 

 form, 4b. 



Fig. 5. — Outline of sa??ie, showing small form inside giant form. 



Fig. 6. — Diagram of Opalina intestinal is, showing cilia all 

 round, ectosarc and endosarc, and rounded nuclei. 



Fig. 7. — Diagram of 0. hinucleata, show^ing anterior and pos- 

 terior nuclei, cilia, and vacuolated protoplasm. Drawn 

 wnth the camera lucida. 



Fig. 8.— Drawing of a living 0. hinucleata as it appears when 

 swimming edge on. 



Fig. 9. — Drawing of same, showing ribbed appearance at the 

 posterior end. 



Fig. 10. — Drawing of 0. hylarum, showing position of nuclei, 

 ectosarc and endosarc. 



Fig. 11. — Transverse section of same, showing arrangement of 

 chromatin material in the nucleus. 



Figs. 12 to 14. — Outlines of three specimens of same, showing 

 different positions of nuclei. In Figs. 12 and 13 the 

 nucleus is dividing ; in Fig. 14 nuclear division is com- 

 pleted and nuclei have taken up their adult positions. 



Fig. 15. — Drawing of same, showing excretory organs. 



Figs. 16 to 18. — Drawing of Copromonas suhtilis. In Fig. 16 

 the adult form is shown; in Fig. 17 longitudinal divi- 

 sion ; in Fig. 18 conjugation. 



Figs. 19 to 22. — Trichomonads. Figs. 19 and 20 represent 

 Trichomonas batrachorum, and Figs. 21 and 22 repre- 

 sent Tricliomastix batrachorum. 



Fig. 23. — Diagram to .show peculiar movements of a dying 

 Trichomonad. 



