The Relation of Mollusks to Fish in Oneida Lake 137 
I. Vurerrante Freepers. 
Vegetable feeders may be divided into the eaters of 
vegetable plankton, alex, slime, dust-fine-detritus, and coarse 
plant-tissues. It has not been possible in the present work 
to differentiate all of these Variations in food habits. 
During the progress of the field work on the lake, precise 
records were kept of the species of plants used by the 
snails for both food and support. In many cases the mol- 
lusks were feeding upon the plant upon which they were 
resting, but it could not always be determined whether the 
plant tissues, or slime or alge were being eaten. In the fol- 
lowing tables all of the molluscan species are listed which 
have been observed on each species of plant. 
A. Species Living on Macroscopic Plants. 
I. Species on submerged stem of Broad-leaved Arrow- 
head (Sagittaria lat ifolia) : 
Galba catascopium, common. Physa ancillaria warreniana, com- 
Planorbis campanulatus, common. mon. 
Planorbis trivolvis, var., not com- 
mon. 
2. Species on stem of Pickerel-weed (Pontederia cor- 
data). 
Planorbis campanulatus, common. Physa ancillaria warreniana, com- 
Planorbis antrosus, not common. mon. 
IManorbis trivolwis, var., not com- Galba catascopium, common. 
mon. Bythinia tentaculata, common. 
Lymnea stagnalis lilliane, rare. 
3. Species on submerged portion of Water Willow 
: I : e 
(Dianthera am ervcana ). 
Lymnea stagnalis lilliane, not Physa ancillaria warreniana, com- 
common. mon. 
Planorbis campanulatus, common. Galha catascopium, common. 
Planorbis antrosus, not common. Bythinia tentaculata, common, 
Planorbis trivolvis, var., not com- Succinea retusa, rare. 
mon. 
