268 NEMATOGEN^E. 



On naked ground, overruning mosses, &c. 



Found in some quantity in one of the stoves of the Eoyal Botanic 

 Gardens, Regent's Park, forming a dark velvety stratum on the stones, 

 walls, &c. 



Plate CVII. fig. "2. a, slightly enlarged, as seen by aid of a pocket 

 lens ; b, trichomes X 400 ; c, portion of same ; d, hormogones X 400. 



GENUS 110. TOLYPOTHR1X. Kutz. (1843.) 



Trichomes spuriously branched, pseudo-branches spreading. 

 Ramifications rarely geminate, oftener solitary, and originating 

 at a point where the continuity of the trichome is interrupted by 

 heterocysts, one or several heterocysts placed directly above 

 each branchlet. 



Tolypothtix flaccida. Kutz. Phyc. Gen., p. 228, 



Crespitose, dark blue-green, trichomes and pseudo-branches 

 elongated, flaccid, arising from a prostrate base, internally pale 

 blue-green, either interrupted or torulose, distinctly articulate 

 (when treated by iodine), joints a little shorter than broad, 

 sheaths colourless, hyaline, rather broad, heterocysts towards 

 the base, subglobose or oblong, two or three together, colour- 

 less. 



SIZE. Trichomes *01 mm. 



Rabh. Alg. Eur. ii., 227. Kutz. Tab. Phyc. ii., t. 32, f. 2. 



In pools, &c. 

 Plate CVlll.Jig. 1. Portions of trichomes X 400 diam. 



Tolypothrix distorta. Kutz. Tab. Phyc. n., t. 33, /. 5. 



Caispitose floccose, bright blue-green, now and then becoming 

 pale, trichomes and pseudo-branches very loosely interwoven, 

 internally blue-green, sometimes apparently continuous, some- 

 times distinctly articulate ; joints equal or a little shorter than 

 their diameter ; sheaths broad, colourless, rarely pale yellow ; 

 heterocysts at the base, or interjected, subglobose or oblong, 

 often 2-3 together. 



SIZE. Trichomes '012 mm. 



Rabh. Alg. Eur. ii., 275. Kirch. Alg. Schl., 228. 



Conferva distorta, Dillw. Conf. t. 21. Eng. Bot. t..2577. 



In swamps. 



"Found occasionally in boggy pools, growing on thick continuous 

 tufts, on decaying grass, and about the steins of aquatic plants, upon 

 small fragments of which it often floats in the autumn on the surface of 

 the water." 



Plate CVI1I. fig. 2 Portion of trichome with hormogone x 400 diam. 



