3IO ZYCJNHMA'rACEAH 



PLATl'. XXXIII 



Spirocvra 



Fic. I. — S. crassoidea, two views of zygospore from Illinois. Figs. 2-4. 

 — 5. hydrodictya, zygospores and gametangia after scalariform conjugation; 

 early stage in lateral conjugation. Note unusual thickness of the tuhe walls. 

 Specimen from Coffeen, Illinois. Fig. 5. — S. texensis, gametangia and zygo- 

 spore from Karnac, Texas. After Taft. Fig. 6. — S. lushanensis, zygospores 

 and gametangia from China. After Li. Figs. 7-8. — S. sirogonioides, scalar- 

 iform and lateral conjugation with resulting zygospores from Charleston, 

 Nova Scotia. After Hughes. Fig. 9. — S. taylorii, gametangia and zygospores 

 from Massachusetts. After Jao. Figs, io-ii. — 5. liana, lateral and scalar- 

 iform conjugation and zygospores from China. Figs. 12-13. — '^- collinili, 

 zygospores formed by lateral and scalariform conjugation from Mississippi. 

 Fig. 14. — 5. chenii, lateral and scalariform conjugation, zygospores, and 

 sterile cell from Szcchwan, China. After Jao. 



