298 ZYGNEMATACEAE 



PLATE XXVII 



Spirogyra 



Figs. 1-2. — S. nitida, gametangia and zygospores from Szechwaii, 

 China. After Jao. Fig. 3. — S. hymerae, vegetative cell, zygospore, and gam- 

 etangia from Indiana. After Britton. Figs. 4-5. — S. setijormis, gametangia 

 and zygospore from Charleston, Illinois. Fig. 6. — S. elliptica, zygospore and 

 gametangia from Szechwan, China. After Jao. Figs. 7-8. — S. wrightiana, 

 vegetative cell, aplanospores, and sporangia from Parahiba, Brazil. Fig. 9. — 

 S. yunnanensis, zygospores and gametangia from Yiinnan, China. After 

 L. C. Li. Fig. 10. — S. hatillensis, zygospores and gametangia from Puerto 

 Rico. Fig. ii. — 5. ellipsospora, zygospore and vegetative cell from Illinois. 

 Fig. 12. — S. emilianensis, zygospores and gametangia from Massachusetts. 

 Fig. 13. — S. exilis, gametangia, zygospores, and sterile cell from l^urma. 

 After West. Figs. 14-15. — S. neglecta, zygospores and gametangia. Mod- 

 ified after Czurda. Fig. 16. — S. decimina, zygospores and gametangia. 

 After Jao. Fig. 17. — S. splendida, zygospore and gametangium. After G. S. 

 West. 



