390 
large part of the section ranged between 7 and 9 feet. Recent maximum 
low-water depths have been mostly 2 to 3% feet more than these. The 
connecting lake and pond acreage in this section at the low levels of 1901 
(219.0 acres per mile) was about twice that between Peoria and Pekin 
per mile of river length, but was not much more than two thirds that 
between Chillicothe and the foot of Peoria Lake, and was less than half 
that between Copperas dam and Havana.* 
Bottom Fauna.—A total of 14 channel collections and 16 shore col- 
lections were made between Pekin and the dam in 1915 at stations as 
shown below. 
Miles 
above Station Channel - |4—7-ft. zone |1—3-ft. zone 
Grafton 
151.5 11%4 miles below Pekin 2 2 
145.6 Opposite Kingston 6 3 3 
141.9 Opposite Spring Lake canal 4 4 4 
136.8 | 100 yards above dam 2 
Total 5 14 9 rf 
The average valuation figure for the channel fauna in the section 
(144.8 lbs. per acre) was lower than in any other important stretch of 
channel between Chillicothe and Havana. The weight of the average 
channel collection was not far from equally divided between the 
Sphaeriidae and the larger Gastropoda, the first contributing 43.7%, the 
Borrom Fauna, CHANNEL, PEKIN TO CorpPpERAS CREEK Dam, 1915 
aoe e Small 
Viviparidae Insects, 
and Bion odes worms, Total 
Pleuroceridae Sphaertidae Crustacea 
Number per sq. yard, 
Average 28.8 126.9 49.8 205.5 
14 collec- 
tions 
Pounds per acre, 
Average 73.3 63.4 8.1 144.8 
14 collec- 
tions 
Per cent. of total, 
(By weight) 50.6% 43.7% 5.7% 
* Table, p. 378. 
