TAXONOMIC KEY 13 



44B Colony with cells equidistant and 



toward periphery Sphaerocystis 



45A Cells with median constriction dividing cell 



into two distinct halves Cosmarium 



45B Cells without pronounced median constric- 

 tion 46 



46A Cells nonflagellated 53 



46B Cells flagellated 47 



47A Cell walls without polygonal plates 49 



47B Cell walls with polygonal plates 48 



48A Cells walls of thick plates with 



distinct sutures Peridinium 



48B Cells walls with faintly distinct 



plates and sutures Glenodinium 



49A Cells uniflagellate 52 



49B Cells biflagellate 50 



50A Cells with two flagella of equal 



length Chlamydomonas 



50B Cells with two flagella of unequal 



length 51 



51 A Cells with single chromatophore Chroomonas 



51B Cells with 2 large chromatophores Cryptomonas 



52 A Cells surrounded by distinct lorica Trachelomonas 



52B Cells without lorica; fusiform to 

 acicular shaped; posterior end 



more or less pointed Euglena 



53A Cells acicular to fusiform with ends tapering 



into long spines Schroederia 



53B Cells without ends tapering into long spines 54 



54A Cells without setae 56 



54B Cells with setae 55 



55A Cells with subpolar or both subpolar and 



equatorial long setae Chodatella 



55B Cells with multiple peripheral long delicate 



setae Golenkinia 



56A Cells long, slender, and tapered at 



both ends Ankistrodesmus 



56B Cells flattened or isodiametric, 

 triangular, quadrangular, or 

 polygonal Tetraedron 



