381 
tance at this place, such vegetation as grows on the west side is usually 
only a thin fringe next the rather steep bank. Outside the 4-foot line 
Peoria Lake has recently been almost entirely free of vegetation, even 
at the lowest gages, and it is consequently much more subject to roiling 
by winds than the narrower and weedier lakes near Havana. 
The Bottom Fauna.—Collections of the small bottom animals, with 
dredges and mud-dipper, were made in the channel July 26 to August 
19, 1915, at four stations in the mud-section between Chillicothe and 
Peoria Narrows; in the hard mud at Peoria Narrows; and in the mud 
opposite the steamboat landing at Peoria. 
CHANNEL COLLECTIONS, CHILLICOTHE TO ProRIA LAKE, 1915 
Depth ad- 
No. col- 
Miles lections apatee, ko 
above Station July— EEC 
Grafton August, 0 y 
1915 ctober, 
1910—1914 
180.5 | Chillicothe 2 28 Deep, narrow river 
177.2 | One mile below Rome 1 12 
175.5 |One and a half miles 
above Spring Bay 3 11 Upper lake, channel 
172.3 | Opposite Mossville 2 19 Middle lake, channel 
| 
166.5 | Peoria Narrows 3 ut) 
162.7 | Opposite Eagle Packet 
landing 4 15 Lower lake, channel 
Total channel collections........... 15 
The average number of bottom animals in a square yard of channel 
bottom, if we except the Peoria Narrows station (which represents a 
very limited area with hard bottom), compared favorably (at 235 per 
sq. yd.) with the figures from some other short reaches between Peoria 
and Havana, but was under the average for the 60.5. miles (416 per sq. 
yd.), and was far below the figure for the very rich section of eight 
miles just above Havana (1,469 per sq. yd.). In all the collections Mol- 
lusca (Gastropoda and Sphaeriidae) were much more numerous than 
insects, worms, and small Crustacea; and the larger Gastropoda (Vivi- 
paridae and Pleuroceridae) were usually more abundant than the 
Sphaeriidae and smaller Gastropoda (Amnicolidae, etc.). 
