than in the basal portion; branched and contorted above. Sheaths 

 thick and colorless, stained violet by chlor-zinc-iodide reagent. Cells 

 1-1.5 fj. in diameter, 4/a long; constricted at the cross walls; cell 

 contents blue-green. 

 Mich. 



Schizothrix lardacea (Cesati) Gomont 1892, p. 307 

 Filaments forming a thick, layered, expanded plant mass, firm 

 but not encrusted with lime; filaments entangled but little-branched; 

 sheaths close, firm, narrowed and pointed at the ends; trichomes not 

 tapering, bluntly rounded at the apex. Cells 1.5-2/x in diameter, 

 2-3/i. long; not constricted at the cross walls, which are usually 

 granular; cell contents blue-green. 

 Mich. 



Schizothrix Muelleri Naegeli in Kuetzing 1849, p. 320 



PI. 114, Fig. 1 

 Filaments free-floating or attached and entangled among other 

 algae; trichomes 1 or 2 within much lamellated, golden-colored 

 sheaths which are attenuate at the apices; cells stout, 6-13/x in 

 diameter, 4-9/x long, slightly constricted at the cross walls; apical 

 cell conically rounded. 



Tychoplankter; in ponds. Wis. 



Schizothrix rivularis (Wolle) Drouet 1942, p. 131 

 PI. 114, Figs. 2, 3 



Trichomes parallel and much entwined, forming cable-like strands 

 or fascicles in copious mucilage; cells quadrate, 5-1 1/a in diameter, 

 not constricted at the cross walls, which are not granular; apical 

 cell bluntly pointed; cells frequently and easily dissociating within 

 the filament, forming interrupted series; sheaths wide and diflBluent; 

 plant mass dark blue-green; individual trichomes bluish or rose- 

 colored. 



When collections of this plant are allowed to stand in water for 

 a short time (overnight), especially in a closed container, large 

 quantities of a water-soluble blue pigment are released. The solu- 

 tion has a beautiful fluorescent property. 



Forming streaming masses in flowing water; attached to sub- 

 merged aquatics. Wis. 



Schizothrix tinctoria Gomont 1890, p. 351 

 PI. 131, Figs. 7, 8 

 Plants forming blue-green penicillate tufts from soft, expanded, 

 gelatinous masses; usually streaming in flowing water. Filaments 



[508] 



