262 NEMATOGEN^E. 



Lyngbya subfusca. (Ag. Syst. p. 64.) 



Substratum velvety, fibrillose, tawny, becoming yellowish, 

 forming a firm compact stratum, of a violet or steel blue colour, 

 changing to brownish ; trichomes rigid, straight, joints about 

 half as long as broad, with a double row of points at the com- 

 missure, apex rather obtuse, naked. 



SIZE. Trichomes -008 mm. diam. Thinner form, trichomes 

 006--007 mm. diam. 



Phormidium subfuscum, Rabh. Alg. Eur. ii., 125. 



On stones in mountain streams. 



Plate CI. fig. 3. a, portions of trichomes X 400, from Scotch speci- 

 ens. J, portions of trichomes from a thinner form X 400. 



mens 



GENUS 105. SYMPLOCA. Kutz. (1843.) 



Trichomes articulate, simple, or only exhibiting the beginning 

 of ramification, more or less distinctly vaginate, ascending from 

 a prostrate base, agglutinated, together in erect or anastomos- 

 ing fascicles, or wick-like bundles, more or less procumbent, 

 coalescing, and often involved in a matrical gelatin. 



Symploca lucifuga, Harv. in Eng. Fl. V., 373. 



Dark seruginous green, fascicles about two lines high, ap- 

 proximate, subuliform, apex at length penicillate ; trichomes 

 single or twin, serugmous, joints equal or a little longer than 

 broad, distinctly granulated, sheaths broad, pellucid, colourless, 

 quite smooth. 



SIZE. Trichomes *0035-'004 mm. diam., including sheath 

 01 mm. 



Rabh. Alg. Eur. ii., 155. 



Oscillator ia lucifuga, Hass. Alg. t. 65, f. 5, 6. Harv. in 

 Eng. Fl. v., 373. 



Calothrix lucifuga, Carm. MSS. 



On pastures and heaths, on decayed alder trunk. 



" Stratum spreading dull blackish green, bristling all over with minute 

 erect fascicles about one third of a line high. Filaments thickish, 

 flexuous, strongly agglutinated together, annulated within, pale 

 yellowish." Harvey. 



Plate CHI. fig. 2. a, portion seen with a pocket lens, b, trichomes 

 X400. 



