383 
A total of thirty collections in the shallower areas between Chilli- 
cothe and the foot of Peoria Lake were taken with the mud-dipper in 
1915; ten within the 4-foot line, and twenty between the 4- and 7-foot 
lines (depths adjusted to gage July—October, 1910-1914). 
SuHore CoLLEcTIONS, CHILLICOTHE TO Foor or PrortA Lakr, 1915 
1- to 3-foot 4- to 7-foot 
Miles above gone ce 
Grafton Station 
Collections Collections 
| 
180.5 Chillicothe are 2 
177.2 One mile below Rome 3 5 
L755 One and a half miles above 
Spring Bay 2 5 
172.3 Opposite Mossville 4 4 
162.7 Opposite Eagle Packet Landing 1 4 
Total collections 10 20 
Average numbers per square yard in the 1- to 3-foot zone (233.7) 
were about the same as in the channel opposite (234.8), but were appre- 
ciably under those found in the 4- to 7-foot zone (314.6). Both in 
the 1- to 3-foot and the 4- to 7-foot zones there were proportionally much 
larger numbers of Sphaeriidae and of insects, worms, and small Crus- 
tacea than were present in corresponding channel collections. 
Bottom Fauna 
1- To 3-rooT Zone, 1915 
NUMBERS PER SQUARE YARD, AVERAGE 
ey Small 
Viviparidae Insects, Col- 
and pee ier worms, Total | lec- 
Pleuroceridae Sphaeriidae Crustacea | tions 
| 
Chillicothe to Mossville 7.7 148.6 76.3 232.6 9 
Peoria Narrows to foot of 
Peoria Lake 50.0 70.0 120.0 | 240.0 al 
Average 236.3 10 
The average poundage per acre of bottom animals in the 1- to 3-foot 
zone* (108.4 pounds) was less than one third the average channel valua- 
*No collections at Peoria Narrows. 
