SCYTONEME^E. 271 



. Stigonema ocellatum. Thur. Ann. Sci. Nat, 1875, I., 377. 



More or less expanded, woolly-toinentose, dark olive brown, 

 cells of the trichome for the most part biseriate, sub-globose, 

 or oblong-compressed, equal or one -third as long as broad, 

 filled with a granular blue green plasma; sheaths very thick, 

 lamellose, dark golden brown, external stratum now and then 

 paler, cells of the branches for the most part uniseriate, ocell ate, 

 sometimes much elongated, apex obtuse, rounded, seldom again 

 branched, sheaths colourless or yellowish, quite smooth. 



SIZE. With sheath about '04 mm. Cells '01--012 mm. 



Kirch. Alg. Schl. 230. 



Sirosiphon ocellatus, Kutz. Tab. Phyc. ii., t. 37, f. 2. Rahh. 

 Alg. Eiir. ii., 286. 



Hassallia oceUata, Hass. Alg. t. 67, f. 2, 7, 6. Fischer 

 Nost., fig. 11. 

 , Conferva ocelluta, Dillw. Conf. t. D. Eng. Bot. i., t. 2530. 



Sct/touema ocellattim-, Haw. Eng. Fl. v., 364. Harv. Man. 

 154. Grev. Fl. Ed. 302. Gray. Arr. i., 285. Eng. Bot. ii., 

 t. 2514. 

 CLCti l*30.*l XT , KenrwAogcrvt**. ifO-tOit 



On inundated ground, in swamps and moors. 



Plate CX. fig. 2. Portion of extremity of trichome X 400. 

 Stigonema Bouteillii. (Breb. Ann. Sci. Nat.} 



*. 



Tufts small, immersed, cushion-like and rounded, dark brown, 

 trichomes very short, variously curved and contorted, olive, or 

 golden brown, sparsely branched, sometimes simple, internally 

 sometimes interrupted, formed from one series of cells one-third 

 or one-fourth as long as broad, branches unilateral, very short, 

 arched, sheaths narrow, colourless or very pale yellow, hyaline 

 and even, or with the outer stratum falling away in fibrils. 



SIZE. Trichome 04- t 06 mm. Cells '01, with envelope '02 

 mm. 



Sirosiphon Bouteillii, Breb. & Desm. in Ann. Sci. Nat. ser. 

 4, Vol. iv., p. 2. 



On calcareous rocks and chalky cliffs. 

 Plate CX. fig. 3. Portion of trichomes X 400. 



Stigonema panniforme. Kirch. Ah/. Schl. 230. 



Forming a thin tomentose stratum, more or less expanded, 

 dark brown, trichomes ascending, very much branched, variously 

 curved, branches unilateral, here and there fasciculate, often ab- 

 breviated, rounded at the apex, internal cells pale blue green, 

 granulose, globose then compressed, arranged in a single, rarely 



