61 
The drop in average weight-valuation of the snail fauna in these four 
lakes, except in the less injured portions of Quiver Lake mentioned, 
amounts to little short of total disappearance—namely, from 122—363 
pounds per acre to nothing at all in Liverpool, Dogfish, and the muddier, 
more stagnant portion of Quiver; and from 409 pounds to 4 pounds per 
acre in Thompson. 
The decrease in snail poundage since 1915 in Thompson Lake, 
where it is in the least ratio, was 99.1 per cent., which is greater even 
than the percentage decline in the river channel between Liverpool and 
Havana. In the Quiver Lake channel the drop in valuation figures since 
1915 is only about 70 per cent:, leaving an average of 248 pounds per acre 
in the limited range in September, 1920. Shoreward on the muddy side 
of Quiver Lake an average valuation of 109 pounds per acre in 1920 
stands without a separate 1914 or 1915 figure for comparison. 
