300 Z^'(;NE\fATACF.AH 



PLATE XXVIII 



Spirogyra 



Figs. i-2.^.S'. plena, receptive gametangia and zygospores formed by 

 lateral and scalaritorm conjugation from Burma. After West. Fig. 3. — S. 

 szcchwanensis, gametangia and zygospore from Chungking, China. After 

 Jao. Fig. 4. — S. jugalis, receptive gametangium and zygospore from Illinois. 

 Fig. 5. — 5. margaritata, receptive gametangium and zygospore from spec- 

 imens collected at Dresden, (jermany. Fig. 6. — S. bichromatophora, gam- 

 etangia and zygospores from India. After Randhavva. Fig. 7. — S. baileyi, 

 gametangia and zygospores from Australia. After Schmidle. Fig. 8. — 5. 

 dubia, gametangia and zygospores. After Kiitzing. Fig. 9. — S. puncticulata, 

 zygospores and gametangia from Massachusetts. After Jao. Fig. 10. — S. 

 aequinoctialis, zygospore and gametangia from central Africa. After West. 

 Figs. 11-13. — S. rhizopus, zygospores, gametangia, holdfast, and details of 

 spore wall, from Peiping, China. After Jao. Fig. 14. — S. dictyospora, veg- 

 etative cell, gametangia, and zygospores from Chungking, China. After Jao. 

 Figs. 15-16. — 5. ]ossa, gametangia, zygospore, and spore wall details from 

 Massachusetts. After Jao. Figs. 17-18. — S. smithii, gametangia, zygospores, 

 and details of outer and inner layers of median spore wall. Figs. 19-20. — S. 

 schmidtii, zygospores and gametangia from Koh Chang, Siam. After West. 



