326 ZVCiNHMATACEAE 



PLATE XLI 



/yg(k7onium, Zygnema, and Spirogvka 



Figs. 1-5. — Zygogonium stephensiae, \egetati\'e cells, and gamctangium 

 (note relative length); iinmaturc and mature zygospores by scalariform 

 conjugation; conjugation through end wall and mature spore; and the only 

 instance of lateral conjugation seen in the abundant collections from Cape 

 Colony. Figs. 6-7. — Zygnema mucigeniim, scalariform and lateral conjuga- 

 tion, and mature spores from northern India. After Randhawa. Figs. 8-9. 

 — Spirogyra sibiriia, bullate sterile cell, scalariform conjugation, zygospores, 

 and spore wall markings from Lake Zaisan region, Russia. After Skvortzof. 

 Figs, io-ii. — 5. czurdae, scalariform conjugation, zygospores, and spore 

 markings from Kashmir, India. After Misra. Fig. 12. — S. australensis, 

 vegetative cells and zygospore from Australia, Queensland. After Mobius. 

 Figs. 13-15. — S. pseudoreticulata, lateral and scalariform conjugation, spore 

 form, and details of spore markings. After Borge. Fig. 16. — S. azygospora, 

 aplanospores, and sporangia from north India. After Singh. Fig. 17. — S. in- 

 signis, vegetative cell, gametangia, and zygospore. After Petit. Fig. 18. — 

 5. macrospora, spores and gametangia from India. After Rao. Fig. 19. — 5. 

 verrucosa, gametangia and zygospores from central India. After Rao. Figs. 

 20-21. — S. indica, lateral and scalariform conjugation. After Rao. Figs. 22- 

 23. — S. marchica, mature spores following scalariform and lateral conjuga- 

 tion. After Krieger. 



