TOLYPOTHRIX. 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 Berkeley ana 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 



