QAvd 
ILLINOIS BIOLOGICAL 
MONOGRAPHS 
eee Py April, 1922 : Riga 
THE MOLLUSCAN FAUNA OF THE BIG 
VERMILION RIVER, ILLINOIS 
wath Sueeiat Reference to its Modiacation as the Result of 
- Pollution by Sewage and Manufacturing Wastes 
WITH FIFTEEN PLATES. 
: i : ; Las Deak ed 
FRANK COLLINS BAKER 
Price $1.25 
: peter BY THE BON renee OF eat) PRESS’ 
UNDER THE AUSPICES OF THE GRADUATE SCHOOL 
_Urpana, TLLINOIS 
