120 ILLINOIS BIOLOGICAL MONOGRAPHS [218 
EXPLANATION OF PLATE 
Fic. 36. Junction of Boneyard with Salt Fork canal, looking west. Note high bank on 
left where mussel shells were found, indicating bottom of bed of Salt Fork stream before the 
canal was dug. Sludge bank in foreground. September 14, 1920. 
Fic. 37. Salt Fork canal three-fourths of a mile below first iron bridge east of Urbana. 
December 31, 1919. 
Fic. 38. Farmer’s bridge across Salt Fork canal, one-half mile below Brownfield Woods 
bridge. December 31, 1919. 
