183 



Fig. 1. Olifjocloniiiin inn quale. Portion of filament. 



Fig. 2 'J'olypothrix brevicellai-is. A — Base of filament. B — False branch 

 and Heterocyst. C and D — Hormogonia, still enclosed in a 

 sheath, adhering to apical portion of a filament. 



Fig. 3. Sligoneina subsalsa, showing development from the Olneocapsa stage of the mature 



filament. 



