TOLYPOTIIRIX. 241 



Hal. Adhering to sticks, stems, &c. ; common. 



This species forms tufts of from half an inch to an inch in 

 height, of a dark green hue, which on drying becomes of an 

 intense verdigris or blue green colour ; the filaments are slen- 

 der, and the branches elongated and simple. 



3. TOLYPOTHRIX BERKELEYANA Carm. 

 Plate LXIX. Fig. 5. ? 



Char. Filaments minute, bright grass green, flaccid, Jlexuous, 

 tufted. Harv. 



Calothrix Berkeleyana Harv. in Hook. Br. Fl. p. 367. ; also 

 in Manual, p. 157. 



" Tufts scattered, about a line in diameter, of a vivid 

 green colour. Filaments twenty to thirty in each tuft, ra- 

 diating horizontally from a central point, exceedingly slender, 

 flaccid, tapering to a hyaline point, variously curved or flex- 

 uous. It comes very near C. confervicola ; but the filaments 

 are much shorter and more slender, and possess nothing of 

 the rigid, erect habit of that species." - Carm. MS. cum 

 icone. 



4. TOLYPOTHRIX NIVEA Hass. 

 Plate LXIX. Fig. 6. 



Char. " Filaments exceedingly slender, rigid, white, forming 

 dirty yellow continuous tufts." Harv. 



Conf. nivea Dillw. t. C. ; E. Bot. 2529. Cal. nivea Harv. 

 in Hook. Brit. Fl. ; also in Manual, p. 157. 



Hob. In sulphur springs, Yorkshire and Durham : Dr. 

 Willan. Near Darlington: Mr. W. Backhouse. Plentiful 

 in sulphur springs, Llanwrtyd, and other similar springs 

 in Great Britain : Dillw. 



" Dr. Willan assures us that this species is found below 

 the spring no further than as the water retains the sensible 



R 



