OSCILLATORIA. 251 



terehriformis, but of a clifFerent colovir, and the striaj are much 

 more evident. 



10. OSCILLATORIA SPLENDIDA Grev. 



Plate LXXII. Fig. 8. 



Char. Stratum bright (sruginous or bluish green, thin, with 



short rags. Filaments arachnoid, straight or curved, 



Strias wholly invisible. 

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



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



O. elegans Ag. 

 Hah. 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 Avhich 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 J<7. 



Plate LXXII. Fig. 7. 



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

 lustre, very lubricous. Filaments very slender. Stria? 

 subdistant. 

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



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

 Hob. Appin : Carmichacl. 



The filaments of this species are very slender, not being 

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

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

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

 distant. 



