52 College of Forestry 
: D. SUMMARY. 
Tt has been shown that the molluscan fauna of Oneida Lake 
is of great variety and abundance and provides a valuable food 
asset for fish. The individuals are abundantly scattered over 
a wide area in the shallow water, each type of habitat — 
shore, boulder-paved, sandy and vegetation-filled — having 
associations of great extent. There is no location in the lake, 
excepting perhaps the deeper portions, where a poor fauna 
exists. This abundance of molluscan life is due largely to 
the shallowness of the lake, which enables a large amount of 
vegetation to find attachment and favorable environmental 
conditions. 
The majority of mollusks are vegetable feeders, including 
desmids, diatoms, filamentous algze, and the tender parts of 
the higher plants. The larger bivalves in addition to algze, 
probably use the dust-fine detritus in the water, as recorded 
by Petersen for the bivalves of Danish marine waters. Many 
snails, as Campeloma, probably also use this detritus as food. 
This dust-fine detritus is made from the breaking up of 
decaying plant.material, which floats about in the water, 
finally falling to the bottom, often at a great distance from 
its original location. Nearly all species of water plants are 
used by mollusks for support or food. A number of species 
prefer dead and decaying vegetation. A few species as 
Lymnea and Physa are omnivorous, eating dead animals, 
rotting plants and fruit as well as living plants. Lymnea 
alone is predaceous, living not only on any weaker creature 
but attacking Planorbis and even its own kind. The data set 
forth in the preceding pages indicates that there is sufficient 
food material to support an abundance of mollusean life 
which consequently forms a valuable food supply for mollusk- 
eating fish. 
