The Relation of Mollusks to Fish in Oneida Lake 283 
Genus PsruposuccingEa Baker. 
57. Pseudosuccinea columella (Say). Fig. 45, No. 38. 
Observed at three stations where the habitat was a pro- 
tected bay filled with floating and submerged vegetation. 
Common on the upper and rare on the lower surface of pond 
lily leaves (Castalia and Nymphea). This Lymnaea is 
widely distributed in the United States and Canada from 
Minnesota eastward and from Manitoba south to Florida and 
Texas. Abundant in New York State, and recorded by 
Beauchamp from Onondaga County. For the use of the 
generic name see F. C. Baker (1911, p- 162). The habitat 
of columella appears to be universally the same, as noted by 
other ecologists. In Tomahawk Lake (p. 239) it was 
observed on lily-pads; in the Georgian Bay region on lily- 
pads; lives also in shallow water clinging to cat-tails and 
reeds (F. C. Baker, 1911, p..170). It is said to feed on 
desmids, diatoms and green algv. 
58. Pseudosuccinea columella chalybea (Gould). Fig. 45, 
No. 387. 
Observed at one station associated with typical columella 
on lily leaves. It is distinguished by its narrower shell and 
higher spire (see F. C. Baker, 1911, p. 171). Not definitely 
recorded from New York previously. The figures of Robert- 
son (pl. XI, fig. 15) represent this race. 
Genus AcreLta Haldeman. 
59. Acella haldemant (Deshayes’ Binney). Fig. 45, No. 
42. 
This rare and peculiar Lymneeid occurred at four stations, 
always in a protected bay where the growth of vegetation 
was luxuriant. Though distributed from Minnesota east- 
ward to Vermont and from Ontario south to Ohio, this deli- 
cate snail has been but little known, especially as regards its 
ecology. Dr. R. J. Kirtland collected it in great numbers 
in Reed Lake, near Grand Rapids, Michigan, and found it, 
