248 ZYGNEMATACEAE 



PLATE II 



Zygnema 



Fig. I. — Usual aiul unusual chromatophores in a filament of Zygnema 

 collected near Fort Myers, Florida. Fig. 2. — Chromatophorc patterns in 

 iilaments from West Point, Mississippi, and Pittsburgh, Pennsylvania. 

 Fig. 3. — Z. oveidanum from Florida, zygospore, parthenospore, and ap- 

 pearance of chromatophores during conjugation. Fig. 4. — Z. himalayense 

 from India, scalariform and lateral conjugation and zygospores. In lateral 

 conjugation the gametes unite through the end walls. After Randhawa. 

 Figs. 5-6. — Z. lacvispoi-um, vegetative cell, scalariform and lateral conjuga- 

 tion, and mature zypospore from Falmouth, Massachusetts. After Jao. 

 Fig. 7. — Z. decussatum, three zygospores and adjoining gametangia from 

 Charleston, Illinois. Fig. 8. — Z. conspicuutn , zygospores and gametangia, 

 from central Illinois. Fig. 9. — Z. lawtonianum, zygospores and gametangia 

 from Medicine Park, Oklahoma. After Taft. Figs, io-ii. — Z. verrucosum, 

 zygospores, gametangia, and details of spore wall, from Szechwan, China. 

 After Jao. Fig. 12. — Z. chungii, zygospore patterns from Wuchang, China. 

 After Li. 



