181] FAUNA OF BIG VERMILION RIVER—BAKER 83 
Collections of materials made just below the third farmer’s bridge, about 
three and a half miles below the Champaign outlet, contained the following 
organisms: 
Blue-green algae Animals 
Phormidium inundatum, abundant. Flagellate Protozoa, very minute. 
Diatoms Euglena geniculata, very abundant. 
Navicula salinarum, abundant. Many in stage of encystment. 
Dineutes assimilis, very abundant. 
On the surface of the water. 
Collections at the Cottonwoods bridge (Fig. 42) contained a larger 
variety of animal life, which was rather meagerly represented above 
this bridge. This place is on the east line of section 11, about four miles 
below the Champaign outlet. The bottom here is of fine sand and mud. 
Blue-green algae Animals 
Phormidium inundatum, abundant. Euglena geniculata, very abundant. 
Diatoms Rotifer, illoricate, one specimen. 
Navicula salinarum, abundant. Limnodrilus, two specimens. 
Dineutes assimilis, a few examples. 
Mussel shells or other mollusks were entirely absent in a living state 
and their shells were notably rare. About three quarters of a mile below 
the first bridge east of Urbana, a half valve of Lampsilis luteola was found 
on a sand bar (Fig. 37). Near the Brownfield woods bridge many broken 
pieces of mussel shells, as well as a few mutilated half valves, were ob- 
served. At a farmer’s bridge half a mile below this bridge several broken 
valves of Lampsilis luteola and Anodonta grandis were collected, (Fig. 
38) and from this point down stream to the Cottonwoods road bridge 
detached valves or broken pieces of shell were more or less common. 
From observations of this and other parts of the stream it seems evident 
that these mutilated shells were washed from the spoil banks on either side 
or from the bed of the old stream channel where it crosses the canal. At the 
junction of the Boneyard with the Salt Fork a layer of these shells was 
observed in the bank, about eighteen inches above the water line (the water 
being low), in a position that indicated the old bed of the Salt Fork before 
the canal was excavated. High water would wash this material way and 
provide the odd valves of mussels observed in different parts of this stream. 
Below Mayview road bridge the conditions are much the same as in 
the neighborhood of the Cottonwoods bridge. The bottom is of sand and 
gravel, with some mud bordering the shore. The water is from a few 
inches to a foot in depth, the channel meandering among a continuous 
series of sand bars. The sand is ripple-marked in places and streaked 
with bands of dark green algae, with yellowish algae in spots. The surface 
of the flowing portion of the stream is thickly covered with patches of dark 
( 
