Myxophyceae X09 



B P'ilaments straight or curved 



a Filaments 1.9 mic. in diameter; apex of trichome bluntly round- 

 ed; cells quadrate or a little longer than diameter 



L. nana 

 b Filaments solitary and scattered; trichomes 1.5-1.8 mic. in diame- 

 ter, somewhat flexuous; cells up to 3.6 mic. in length 



L. subtilis 

 c Filaments 1.8 mic. in diameter, at first attached, afterwards free, 

 short, straight or slightly curved; cells about equal in length 

 to the diameter L. distincta 



(2) Sheaths more or less thick and gelatinous 

 A Plant mass ochre-yellow in color; sheaths at first thin, colorless, 

 later thick and yellowish; trichomes .9 mic. in diameter, espe- 

 cially constricted at joints, frequently interrupted 



L. ochracea 

 B Plant mass rust-colored; sheaths at first thin, colorless, later 

 thicker and rust-colored; trichomes .8-.9 mic. in diameter, 

 not constricted at joints, continuous 



L. ferruginea 



II Trichomes 2-6 mic. in diameter; sheaths usually thin and colorless, 



sometimes becoming thick and yellowish 



I Plants living in salt water, sometimes in brackish, fresh or hot water 



(i) Filaments coiled, densely entangled; sheaths thin, colorless, later 



becoming thick and lamellose; trichomes 2.5-6 mic. in diameter, 



not constricted at joints; cells 1.5-5.5 mic. in length 



L. lutea 



(2) Plants living in salt water, epiphytic; sheaths thin, delicate; trich- 

 omes 3-4.5 mic. in diameter, constricted at joints; cells up to 

 13 mic. in length L. holdenii 



2 Plants living in fresh water; sheaths usually thin and colorless 



(i) Plant mass caespitose, light green; trichomes 2-3 mic. in diameter, 

 not constricted at joints; cells 1-3.7 mic. in length 



L. digueti 



(2) Plant mass caespitose, blue-green; sheaths delicate, smooth, usually 



inconspicuous; trichomes 3-2-3-5 mic. in diameter, somewhat 

 rigid, forming tufts L- penicillata 



(3) Plant mass dull blue-green; trichomes 4-6 mic. in diameter, not 



constricted at joints; cells 2.3-3 mic. in length 



L. aerugineo-caeru- 

 lea 



(4) Plants epiphytic; filaments straight or sharply curved and twisted; 



trichomes 5-6 mic. in diameter, not constricted at joints 



L. cladophorae 



(5) Plant mass at first adherent, afterwards free, rust-colored on the 



outside, olive green within; sheaths colorless, sometimes yellow- 

 ish, slightly mucous and agglutinated, thick; trichomes 2.8-3.2 



