212 ILLINOIS BIOLOGICAL MONOGRAPHS [450 



EXPLANATION OF PLATE 



Figs. 1 to 5. Leptotheca agilis. 



Fig. L A typical trophozoite j« Diw. After Thelohan (1895, Fig. 29); X 750, 



Fig. 2. A young form. After Thelohan (1895, Fig. 31). X750. 



Fig. 3. A trophozoite in motion. After Doflein (1898, Fig. 5). 



Fig. 4. A trophozoite in contracted condition. After Doflein (1898, Fig. 7). 



Fig. 5. A fresh spore. After Thdohan (1895, Fig. 30). X1500. 



Fig. 6. A fresh mature spore of Leptotheca dongata. After Thelohan (1895, Fig. 38). 



X1500. 

 Fig. 7. klKs\xm&tnxt^>OKol Leptotheca paroa. After Thdohan (1895, Fig. 25). X1500. 

 Fig. 8. A fresh spore of Leptotheca perlata. After Balbiani (1884, Fig. 40). 

 Fig. 9. A spore ol Leptotheca tnacrospora. After Auerbach (1909, Fig. 2a). X1350. 

 Fig. 10. A spore of Leptotheca informis, preserved in formol. After Auerbach (1910b, Fig. 



la). X about 2000. 

 Fig. 11. A spore of Leptotheca longipes, preserved in formol. After Auerbach (1910b, Fig. 



Id). X about 2200. 

 Fig. 12. A fresh spore of Leptotheca fusifortnis. After Davis (1917, Fig. 1). X 1500. 

 Fig. 13. Airtsh. spore oi Leptotheca scissura. After Davis (1917, Fig. 8). X1500. 

 Fig. 14. A fresh spore of Leptotheca lobosa. After Davis (1917, Fig. 11). X1500. 

 Fig. 15. A fresh spore of Leptotheca glomerosa. After Davis (1917, Fig. 13). X1500. 

 Fig. 16. A trophozoite of Leptotheca sp. After Awerinzew (1908, PI. 2, Fig. 14). 1/12 



and comp. oc. 12. 

 Fig. 17. Another trophozoite of the same. After Awerinzew (1908, PI. 2, Fig. 17). 1/12 



and comp. oc. 12. 

 Figs. 18 to 20. Ceratomyxa arcuata. After Thelohan (1895). 

 Figs. 18 and 19. Typical young form. After Thelohan (1895, Figs. 16 and 17). 

 Fig. 20. A trophozoite with two spores. After Thelohan (1895, Fig. 18), 



