oe 
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00000000 
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Bacillariaceae 
No. per m3 
a 
= 
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y 
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== +-4-—...s- 
—— == 
~ 
Nitrates 
Parts perM 
N 
peare lie} 
Pa ereenee tesco rN 
oh en as se me ee vee ee —U0J WU) 
ydeibousay | 
Bee), SS 
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0 0 
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v 0/ 
gS 
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8 0 
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| t] 
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=e} ef e 
$2} 295 
plankton, 
Illinois River at Havana for 1898. 
Fig. A.—Diagram showing the seasonal distribution of diatoms, total 
nitrates, and thermograph and hydrograph of 
