Spbaeropborus 

 Sphaerospora 

 Spaerostilbe . 

 Sphaerotbeca 

 Spbaerozosma 

 Sphaerulina . 

 Sphinctrina . 

 Spiloma . . 

 Spilonema 

 Spinellus . . 

 Spii'illum . . 

 Spirogyra. . 

 Spirotaenium 

 Sporocbnus . 

 Sporodinia . 

 Spoi'omega . 

 Sporormia 

 Spumaria . . 

 îStammaria , 

 StaurastruHi , 

 Staurogenia , 

 Stauroneis , 

 Staurospermum. 

 Stegia . . . 

 Stemonitis . 

 Siephanodiscus 

 Stereocaiiloa. 

 Stichococcus. 

 Stictina . . 

 Stictis . . . 

 Stigeoclonium 

 Stigmatea . . 

 Stigonema 

 Streptococcus 

 Striatella . . 

 Stypocauion . 

 Su ri raya . . 

 Synalissa . . 

 Syncephalastrum 

 Syncepbaiis . 

 Syncbytriuin 

 Syncripta . . 

 Synedra. 



Tabellaria 



Taoriia . . 



Tapesia . 



Taphrina . 



Teichospora 



Tetmemorus 



Tetracyclus 



Tetraedron 



Tetramitus 



Tetraspora 



Thalloidima 



Tliamnidion 



Thelenella 



Tbelidium 



Thelotreraa 



Thorea. . 



Tbyndaria 



Tilmadocbe 



Toiypella . 



Tolypellopsis 



Tolypothrix . 



