The Relation of Mollusks to Fish in Oneida Lake 279 
stations, all more or less exposed points, bays, and shores. 
In the Saginaw Bay region it was found along the shores 
of the Pigeon River among. alge, principally Vaucheria; 
also dredged in deep water (H. b. Baker, 1911, p. 164); in 
the Georgian Bay region if occurs in weedy sand runs and 
weedy muddy bays and on rocks (p. 100); at Isle Royale it 
was found on a mud bottom in three to five feet of water (p. 
292). Listed by Beauchamp (as bicarinatus) from Onon- 
daga County and commonly distributed in New York State. 
Antrosus has been observed on the following plants: 
Pickerel-weed (Pontederia cor- Lake Bulrush (Scirpus occiden- 
data). talis). 
Water Willow (Dianthera ameri- 
cana). 
Observed to feed upon green alge, and is eaten by the 
Pumpkinseed. 
52. Planorbis campanulatus Say. Fig. 47, Nos. 18-16. 
This is one of the most abundant mollusks in the lake, 
being found at 32 stations. It occurs in all kinds of habi- 
tats from the wave-beaten shore to the quiet, protected bay. 
It clings to stones, the sandy bottom, and to any kind of 
vegetation. In the Saginaw Bay region, campanulatus lives 
in pond-like bodies of water on lily leaves and Potamogeton 
(p. 165); in the Georgian Bay region it occurs in weedy 
places, both muddy and sandy, up to the depth of at least 
three fathoms (p. 100); at Isle Royale it occurred in mud 
and among loose stones at a depth of about one foot and in 
small pools among sedge (p. 293). In Tomahawk Lake it 
lived on both a protected and an exposed habitat in much 
the same manner as in Oneida Lake (p. 236). A single 
specimen was found in Oneida Lake which had the elevated 
apical whorls characteristic of the variety rudentis Dall. 
Campanulatus is abundant in New York State, and is listed 
Fig. 47. 1, 3, Galba emarginata; 2, 4-8, Galba catascopium; 9-12, 
Goniobasis livescens ; 13-16, Planorbis campanulatus ; 17-20, 
Planorbis antrosus. 
