248 OSCILLATORE^. 



4. OSCILLATOKIA TENUIS Ag. 



Plate LXXIL Fig. 1. 



Char. Stratum i-ich dark green, very thitiy gelatinous, with 

 short rays. Filaments pale green, straight. Striae sub- 

 distant, evident. 



Grev. Edin., p. 303. ; Harv. in Hook. Brit. Flor. 374. ; 

 Harv. in Manual, p. 163. O. limosa Hook. Scot. ii. 

 p. 79. Conf. limosa Dillw. t. 20. O. viridis Jolmst. 

 Berw. Flor. p. 264. 



Hab. Common in ditches. 



" In muddy ditches, at first resting at the bottom, but gra- 

 dually rising in bullated strata to the surface, common; stratum 

 extensive, glossy when dry, in which state it fully preserves 

 its colour. Filaments, of half the diameter of those of O. li- 

 mosa, pale green ; strife distant and indistinct. It adheres 

 strongly to paper." — Harv. The stratum of this species 

 exactly resembles that of O. limosa, and the filaments, like it 

 also, contract somewhat in drying ; they are, hoAvever, two 

 or three times smaller ; the stria3 more distant, and not so 

 strongly marked. 



5. OSCILLATORIA CYANEA Ag. 



Char. " Glaucous blue. Filaments simple, entangled, cylin- 

 drical, even, with a deciduous coat. Joints obsolete, about 

 as long as broad." — Sm. 

 Harv. Hook. Br. Fl. p. 374. Conferva cyanea, E. B. 



t. 2578. ; Harv. Manual, p. 163. 

 Hah. Damp walls on the inside of several Suffolk churches ; 

 at Icklingham and Hengrave ; also in Lincolnshire : Sir 

 Thomas Gage, Bart. 



" On the wall it is conspicuous for its light sky-blue colour, 

 like some sort of mucor. Under a high magnifier, and 

 when moistened, it is found to consist of minute, even, simple, 

 entangled threads, one five hundredth part of an inch in dia- 



