sample collected at this site during a 15-minute scan under low 

 power (lOOX) . A diatom slide was not prepared. This site is 

 evidently pristine with very little algal growth. 



Cottonwood Creek Station 2. The Schizothrix in this sample 

 appeared as rubbery and pustular macroscopic colonies up to 1 cm 

 across. Phorrnidium and Protoderma were epiphytes on Tetraspora. 



Rock Creek Station 1. This sample contained one small rock, 

 which I brushed with a toothbrush into the sample container. 

 Hydrurus occurred in this sample as scattered cells. 



Rock Creek Station 2. This sample was very sparse and 

 consisted mostly of roots from terrestrial plants. 



NON- DIATOM ALGAE 



The periphyton sample from Cottonwood Creek Station 2 



contained a healthy mix of diatoms, cyanobacteria, and green 

 algae (Table 4) . Tetraspora, a green alga that is characteristic 

 of cold, fast -flowing mountain streams, was dominant. Diatoms 

 ranked second in biovolume and various genera of cyanobacteria 

 ranked third through fifth. Ulothrix, another green alga typical 

 of cold waters, was common and ranked sixth. 



The sample from Rock Creek Station 1 also contained a mix of 

 chrysophytes (including diatoms) , cyanobacteria, and green algae. 

 The most abundant alga at this site was Hydrurus foetidus, a 

 common chrysophyte in mountain streams . Diatoms ranked second in 

 biovolume, followed by green algae and cyanobacteria (Table 4) . 



The sample from Rock Creek Station 2 was very sparse. Only 

 one cell of Closterium (a green alga) and several diatoms were 

 observed during a 15-minute scan. This site probably supported 



8 



