92 K. MUNSTER STROM 



Genus Phormidiiini Kuetz. 



21. Phormidium Retzii (Ag.) Gom. 



Gomont in Journ. de Botanique IV; Agardh: Disp. Alg. Suec. 



The form observed no doubt belongs to this species, but presents some 

 likeness to Phormidium ambiguum. 

 Size: lat. fil. 6 — j \i.. 



Masafuera: forming a stratum in waterfall. 

 Area of distribution: ubiquitous. 



22. Phorrnidium uncinatum (Ag.) Gom. 



Gomont in Journ. de Botanique IV; Oscillatoria uncinata Agardh in Flora X; 

 Wittrock & Nordstedt: Exsicc. No. 96, » Phormidium membranaceum». 



Masatierra: The typical form was observed in a single sample. 

 Area of distribution: world-wide. 



Genus'Oscillatoria Vaucher. 



23. Oscillatoria tenuis Ag. 



Agardh: Alg. Dec. 



Masatierra: This common species was present in one sample, from wet 

 rocks in Pangal. 



Area of distribution: one of the most generally distributed Algae in the world. 



24. Oscillatoria sp. 



.- Oscillatoria terebrifon/iis forma tenuis W. & G. S. West: Freshwater Algae. 

 British Antarctic Expedition 1907 — 9. 



In one sample there was an Oscillatoria, which presented a striking simil- 

 arity to the forma tenuis described by Messrs. West from the Antarctic. The 



Fig. 1. Ca. 1,000 X- 



dimensions were just the same, and also the cytological structure as far as it 

 could be observed (the specimens were preserved in formaline solution), but the 

 filaments were very little, if at all, terebriform. However, if to judge from 

 Messrs. West's figures, this character is not very striking in the specimens 



