272 NEMATOGEN.E. 



in a double series, sheaths narrow, brown or yellow brown, paler 

 at the tips or almost colourless. 



SIZE. Trichomes -Q35--05 mm. 



Eng. Fl. v., 363. Hass. Alg. 229, t. 66, f. 4, 5. Harv. 

 Man. 153. 



Sirosiphon panniformis, Kutz. Tab. Pbyc. ii., t. 36, f. 2. 



Scytonema panni forme, Ag. Syst. p. 39. 



On rocks, stones, &c. 

 Plate CX. fig. 4. Portion of trichouies X 400 diam. 



J&f . ' ~^U>~^T 



Stigonema mamillosum. (Ag.} Kutz. Tab. Pliyc. n., t. 37, /. 4. 



Forming continuous tufts several inches in diameter, branches 

 simple, their diameter being greatest in the middle, and beset 

 on all sides with mamillae of various sizes. 



SIZE. Trichome -06-' 1 mm., very variable. 



Kirch. Alg. Schl. 229. Rabh. Alg. Eur. ii., 291. Eng. Fl. 

 v., 363. Hass. Alg. 228, t. 66, f. 2, 3. Harv. Man. 153. 

 Mack. Hib. 236. 



Rocky bottoms of sub-alpine rivulets. 



Plate CXI. fig. 3. Portion of young trichome X 400, becoming more 

 opaque with age. 



Stigonema compactum. Kirch. Alg. Schl. 230. 



Forming an expanded compact tomentose dark brown stratum, 

 trichomes and branches ascending, a little attenuated at the 

 apices, obtuse, internally formed of a single, rarely a double 

 series of cells, which are torulose and almost moniliform, 

 diameter and length nearly equal, filled with a pale bine-green 

 granular plasma, sheaths firm, golden brown, heterocysts sub- 

 globose or oblong. 



SIZE. Trichomes '015-'016 mm. 



Sirosiphon compactus, Kutz. Tab. Phyc. ii., t. 36, f. 3. Rabh. 

 Alg. Eur. ii., 287. Leight. Lich. Flora, p. 9. 



Hassallia compacta, Hass. Alg. 232, t. 68, f. 3. 



Scytonema compactum, Eng. Fl. v., 365. Harv. Man. 154. 

 Grev. Ed. 302. 



On wet rocks. 



Plate CXI. fig. 4. Portions of trichomes X 400 diam. 



yK*. 

 Stigonema turfaceum. (Berk. Eng. Bot. Supp. t. 2826, f. 1.) 







Pulvinate, deep olivaceous black, 2 lines thick. Trichomes 

 very thick, much branched, golden yellow, becoming brownish, 



