The Relation of Mollusks to Fish in Oneida Lake 
Planorbis parvus, on lily 
under side. 
Planorbis crista, on lily pads, un- 
der side. 
Ancylus parallelus, on lily pads, 
under side. 
Physa heterostropha, on lily pads, 
and among Potamogeton. 
Physa gyrina, on lily pads. 
Physa integra, among Vaucheria 
and on lily pads, under side. 
pads, 
149 
Goniobasis livescens, an Potamoge- 
ton, 1 specimen. 
Amnicola limosa, on lily 
Potamogeton, in alge. 
Spherium solidulum, among Vau- 
cher. 
Musculium 
Sphagnum. 
Musculium securis, among Sphag- 
num. 
pads. 
truncatum, among 
F. C. Baker (1911, pp. 235-240) records a number of 
mollusks in relation to vegetation, as noted below: 
Aneylus parallelus, on lily-pads, 
under side. 
Planorbis parvus, on lily pads, un- 
der side. 
Pseudosuccinea calumella, on lily 
pads. 
Galba lanceata, on leaves of Typha 
latifolia. 
ENS 
Species Livine on Antmat Foon, Prepacrous IN 
Part. 
Only a very small percentage of fresh water mollusks are 
predaceous. Dr. Jean Dawson has summarized the food 
habits of the fresh-water pulmonates, and we cannot do better 
than quote from her valuable paper (1911, p. 84). “ Physa 
is almost omnivorous in its food habits, feeding upon a 
variety of plant and animal forms, fresh or in various stages 
of decay. Lymnea stagnalis, L. palustris and L. reflexa have 
carnivorous and cannibalistic traits while the genus Physa 
is not known to take living prey. Planorbis trivolvis and P. 
bicarmata (antrosus) on the other hand have a vegetable 
diet only. The conditions of the habitats determine largely 
the food eaten by the snail, the greater variety being found 
in still water.” 
Both Physa and Lymnea are good scavengers. The writer 
has observed Lymnea stagnalis appressa and Galba palustris 
on dead bodies of cats, dogs, and fish floating in the water. 
Several biologists have experimented with species of the 
family Lymneide with interesting results. Thus, Walter 
(1906, p. 21) remarks that Galba palustris “ feeds readily on 
dead flies, tadpoles and its own eggs, as well as on other snails 
