350 Notes on Marine Algoe. By Edward A. L. Batters. 



green colour, on mud and decaying algse. Several heterocysts 

 in each filament. Spores one on each side of the heterocyst, 

 oblong, about twice as long as broad, brownish green when 

 mature. 



Estuary of the Tweed and on the muddy banks of the river 

 between the two bridges on the Berwick side. Eaie. 



2. SpirvMna tenuissima. Kut%. Phy. Gen. p. 183. Sarv. 

 Phyc. Brit., PL 105, c. 



Pilaments excessively slender, twisted into a spiral, forming a 

 thin, bright metallic or verdigris-green stratum on mud. 



My specimens come very near Crouan's Spirulina pseudo- 

 tenuissima. The spiral is more open and the threads finer than 

 Harvey's plate would lead one to suppose is the case with S. 

 tenuissima. It is therefore with considerable doubt that I have 

 referred the Berwick plant to the present species. I have only 

 met with this plant on one occasion, when I found a considerable 

 quantity between the old bridge and the railway bridge on the 

 Tweed, but only secured a small quantity for examination. On 

 returning the next day I found the mud had been disturbed and 

 not a vestige of the Spirulina remained. Bare. 



3. Oscillatoria littoralis. Carm. Alg. Appin. ined. Rarv. 

 Phyc. Brit., PI. 105. A. 



A thin membranaceous dark green stratum covering the bot- 

 tom of muddy pools near high water mark. Filaments usually 

 twisted into bundles, straight or slightly curved. Striae well 

 marked at intervals of about one third the width of the filament. 

 The stratum peels off the rock in the form of a dirty green mem- 

 brane which does not adhere to paper at all well. 



Damp rocks near high water mark between the pier and the 

 <' Greenses " Not uncommon. 



4. Oscillatoria subuliformis. Thtoaites in Sarv. Phyc. Brit., PL 

 251. B. 



Stratum of dark green colour, soft, gelatinous. Filaments 

 very slender, tapering to an incurved point. Striae indistinct and 

 separated from each other by intervals of half the width of the 

 filament. 



The Coves at Dodd's Well, and on the sand at the mouth of 

 the river. Not uncommon. 



5. Oscillatoria nigro-viridis. Thw. in Harv. Phyc, Brit., PL 

 251. A. 



A dark olive green almost black stratum (a rich metallic green 



