OSCILLATORIA. 251 



terehriformis, but of a diiFerent colour, and the stria? are much 

 more evident. 



10. OSCILLATORIA SPLENDIDA Grev. 



Plate LXXII. Fig. 8. 



Char, Stratum bright (Bruginous or bluish green, thin, with 

 short rays. Filaments arachnoid, straight or curved. 

 Striae loholly invisible. 



Grev. Flor. Edin., p. 304. ; Harv. Br. Flor. 375. ; Harv. 

 Manual, p. 164. O. membranacea, O. amphibia and 

 O. elegans Ag. 



Hab. In tubs of water in the stove of the Botanic Garden, 

 Edinburgh : Dr, Greville. 



This is the most slender of all the Oscillatorice. The 

 stratum exactly resembles in colour and appearance that of 

 either O. limosa or O. tenuis, from which it may be imme- 

 diately detected by the microscope. Agardh has described 

 this species under no less than three different names, as I 

 have ascertained from an examination of authentic specimens 

 in the Herbarium of Sir W. J. Hooker. 



11. OSCILLATORIA AUTUMNALIS Ag. 



Plate LXXII. Fig. 7. 



Char. Stratum of a deep (Bruginous green, with a metallic 

 lustre, very lubricous. Filaments very slender. Stride 

 subdistant, 



O. autumnalis Ag. Syst. p. 62. ; Grev. Flor. Edin. p. 305.; 

 Harv. I.e. p. 376.; Harv. Manual, p. 165. 



Hab. Appin : Carmichael. 



The filaments of this species are very slender, not being 

 more than twice the diameter of those of O. splendida. They 

 cohere closely, and are usually very much broken when ex- 

 amined under the microscope. Stride not very evident, sub- 

 distant. 



