Table II 



RELATIVE ABUNDANCE (%) OF DIATOM TAXA 



Yellowstone R. Bighorn R. Yellowston R 

 Taxa @ Custer @ Bighorn @ Myers 



Achnanthes deflexa 1.3 0.6 



Achnanthes lanceolata 0.3 



Achnanthes minutissima 9»2 



Amphora ovalis v. pediculus 3«6 

 Biddulphia laevis 



Caloneis amphisbaena 0.3 



Cocconeis pediculus 0.7 



Cocconeis placentula v. euglypta 9«9 



Cyclotella glomerata 0.3 

 Cymatopleura solea 



Cymbella affinis 1.0 



Cymbella microcephala 0.7 



Cymbella prostrata t t 



Cymbella sinuata 4.6 0.5 2.7 



Cymbella turgida t 



Cymbella ventricosa 2.0 0.8 0.9 



Diatoma anceps 1.3 



Diatoma tenue t 



Diatoma vulgare 0.7 3.2 1.8 



Diatoma vulgare v. breve t 



Epithemia sorex 0.7 t 0.3 



Epithemia zebra v. saxonica t 



t = trace 



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