net BULLETIN 
OF THE 
ILLINOIS STATE LABORATORY 
OF 
NATURAL HISTORY 
URBANA, ILLINOIS, U. S. A. 


Wet. VT, MAY, 1908 ARTICLE I. 

THE PLANKTON OF THE ILLINOIS RIVER, 1894-1899, witTH 
INTRODUCTORY NOTES UPON THE HYDROGRAPHY OF THE ILLINOIS 
RIVER AND ITS BASIN. PART II. CONSTITUENT ORGANISMS AND 
THEIR SEASONAL DISTRIBUTION. 
BY. 
Cie ROPOID Pm’. 
