1731 FAUNA OF BIG VERMILION RIVER— BAKER 75 



and similar wastes. Ortmann's work on the rivers of western Pennsylvania 

 clearly indicate the baneful results of such pollution (Ortmann, 1909). 



The Boneyard is apparently now barren of all clean water life. Fre- 

 quent examinations made during 1918 failed to supply any life of this 

 character. Fresh water pulmonate mollusks, and Cambarus and other 

 smaller Crustacea were once abundant, but appear to be wanting at the 

 present time. A large snapping turtle was observed in the Boneyard near 

 Lincoln Avenue, in 1918. The ditched portion of Salt Fork above Urbana, 

 is a clean water stream, filled with aquatic life, which abruptly terminates 

 at the junction of this stream with the Boneyard, with its load of sewage 

 from Urbana. From here to a point fourteen miles below Urbana not a 

 living mussel was found, and no air breathing snails were observed, except 

 in one instance, believed to have been introduced from a near-by portion 

 of the old river bed, which still retains clean water life, above St. Joseph, 

 a distance of ten miles below Urbana. The large number of empty valves 

 and paired shells of the river mussels below St. Joseph indicate an environ- 

 ment that has become, more or less recently, inimical to these creatures. 

 Crayfish were also absent from the same area. 



Habermeyer's report of Salt Fork, October 1, 1917, describes condi- 

 tions as follows: "The stream below the Champaign outlet to the north 

 line of section 10, one and a half miles below the outlet, was in very foul 

 condition. At tb^ east line of section 11, four miles below the Champaign 

 sewer outlet, the stream appeared to be quite clear and there was no 

 offensive odor noticeable. At the outlet of the west branch of Salt Fork, 

 the water was clearer than that in the north branch (Spoon River). A 

 resident near the junction of the two branches stated that at times when 

 the creek flow increased, foul matter was washed down from above and 

 there was considerable odor in the vicinity for a day or two." 



The dredging of a new channel has been responsible for the water 

 being clearer at times in Salt Fork than in Spoon River, providing a sand 

 bottom which is hard and resistant and has not yet silted up to any degree. 

 Spoon River has a mud bottom and the waters are turbid a large part of 

 the time. In a photograph of the Salt Fork taken some eight miles below 

 Urbana (two miles northwest of St. Joseph), the water was so clear that 

 the ripple marks on the sandy bottom may be distinctly seen in the picture 

 (Fig. 45) yet the stream at this point was totally barren of clean water 

 life and the water was laden with masses of decomposing matter, made up 

 of foul water algae and Protozoa, and the bottom was filled with slime 

 worms (Limnodrilus). Below the junction of these two branches, bottom 

 conditions are still very bad, and clean water life does not appear for a 

 distance of several miles, as has already been shovvn. 



The people mentioned in the report were interviewed in 1918. They 

 reported that no trouble was experienced during periods of low water, but 



