Lhe Relation of Mollusks to Fish in Oneida Lake 113 
F. SUMMARY. 
The habitats analyzed may be reduced to three general 
types. 1, boulder bottom; 2, sandy bottom; and 3, vegetation- 
covered bottom. ‘The first is usually subject to rough water 
and has little or no vegetation; the second is more ox Jess pro- 
tected from rough water and has considerable vegetation; the 
third is generally adequately protected from rough water and 
supports a maximum amount of vegetation. In no habitat 
does the depth of water exceed 10 feet and the average is 
about 3 feet. The greatest number of molluscan species (39) 
is found in the second type, the sandy bottom. These three 
tvpes of habitat are found in all parts of the lake examined. 
The absence of mud, except in small isolated spots, is of 
special interest. With one exception, the fresh water 
molluscan fauna of this lake is greater in number of species 
than that of any similar body of water in the United States. 
