98 ILLINOIS BIOLOGICAL MONOGRAPHS [196 
EXPLANATION OF PLATE 
Fic. 1. Drainage ditch above Urbana, east of cemetery. Station 2. 
Fic. 2. Salt Fork south of Muncie. Note water willow in center of stream bed; also 
numerous bare portions of stream bed, the river appearing as a series of pools. October, 1919. 
Station 26. 
