PLATE I. 



Fig. 1. Arcella. 



,, 2. Actinosphaerium Echhornii. 



3. Opalina ranorum. 



,, 4. Paramoecium. 



,, 5. Trachelocerca. 



,, 6. Amphileptus. 



,, 7. Spirostomum 



,, 8. Balantidium entozoon. 



,, 9. Nyctotherus cordiformis. 



10. Stentor. 



11. Oxytricha. 



12. Stylonichia. 



13. Euplotes. 



14. Vorticella. 



15. ,, (portion more highly magnified). 



16. Epistylis. 



,, 17. Coleps. 



,, 18. Euglena viridis. 



19. ,, ,, (showing another stage of movement). 



,, 20. Euglena longicauda. 



21. Euglena pleuronectes. 



,, 22. Noteus quadricornis. 



,, 23. Brachionus. 



,, 24. Anuraea. 



25. Mastigocerca. 



,, 26. Euchlanis. 



,,. 27. Lepadella. 



28. Salpina. 



29. Rotifer vulgaris. 



30. Chaetonotus. 



(N.B. During the process of reproduction the figures have been 

 reduced by l-20th.) 



