6. Cells shorter than broad. S. vaginata 



6. Cells quadrate or longer than broad - 7 



7. Filaments forming streaming penicillate tufts S. tinctoria 



7. Filaments forming cushion-like or thick, expanded masses 8 



8. Plant mass encrusted with hme; trichome 1.4-3^ in diameter; cells 

 1.2-3.5/a long; apical cell briefly tapering ____ S. fasciculata 



8. Plant mass not at all or but very httle encrusted with lime; 

 trichomes 1-1. 5^ in diameter; cells 4^ long; apical cell bluntly 

 rounded, not tapering S . lacustris 



Schizothrix fasciculata ( Naeg. ) Gomont 1893, p. 298 

 Filaments united to form a pulvinate, sometimes expanded mass, 

 thickly encrusted with lime, often forming pebbles; filaments densely 

 entangled, expanding and forked above and involving many tri- 

 chomes, but narrower below ( toward the base of the plant mass ) ; 

 sheaths thick; cells 1.4r-Six in diameter, 1.2-3.5/^ long, constricted at 

 the cross walls; apical cell sharply conical; cell contents blue-green. 

 Mich. 



Schizothrix Friesii Gomont 1892, p. 316 

 PL 114, Fig. 5 

 Trichomes solitary or 2-3 (rarely 4-5) within dichotomously 

 branching sheaths which taper at the apices, the envelopes color- 

 less and smooth although roughened in age, sticky and united to 

 form branched and anastomosing, erect tufts; cells cyhndrical, con- 

 stricted at the cross walls; apical cell bluntly conical; cells 3-6/x in 

 diameter, 4-6- ( 12 )^ long. 

 On submerged logs. Wis. 



Schizothrix fuscescens Kuetzing 1843, p. 230 

 PI. 114, Fig. 4 



Trichomes few and entwined within a soft, gelatinous sheath 

 which usually is colorless without but golden-yellow within, form- 

 ing mucilaginous masses on moss or on partly submerged substrates; 

 trichomes not at all tapering toward the apices, which are bluntly 

 rounded; cells 2.8-3/x in diameter, 8-13;a long, constricted at the 

 cross walls. 



Forming thin, golden-colored or brownish strands on mosses in 

 a Sphagnum bog. Wis. 



Schizothrix lacustris A. Braun in Kuetzing 1849, p. 320 



PL 131, Fig. 6 

 Filaments united to form a pulvinate mass, not encrusted with 

 lime, expanded and containing more numerous trichomes above 



[507] 



