Table 4. Relative abundance of cells and rank by biovolume of 

 diatoms and genera of non-diatom algae in periphyton 

 samples collected from Cottonwood Creek and Rock 

 Creek near Clyde Park, Montana in the summer of 2000. 



Relative Abundance and (Rank) 

 Taxa Cottonwood Creek Rock Creek 



Station 2 Station 1 Station 2 



Chlorophyta (green algae) 



Cladophora occasional (8) 



Closterium 



Coswari urn 



Oedogonium 



Protoderwa 



Scenedesmus 



Spirogyra 



Tetraspora 



Ulothrix 



Zygnema 



occasional (9) 

 occasional (10) 



common (7) 

 occasional (11) 



dominant (1) 

 common (6) 



occasional (4) 



occasional (5) 



occasional (6) 

 common (3) 



rare (2) 



Chrysophyta (golden algae) 



Diatoms abundant (2) frequent (2] 



Hydrurus foetidus abundant (i; 



occasional (1) 



Cyanophyta (cyanobacteria) ^ 



Oscillatoria frequent (5) 



Phormi di urn abundant ( 4 ) 



Schizothrix frequent (3) 



occasional (7) 



^ Formerly known as blue-green algae. 



