LYMNZIDA OF NORTH AMERICA. 427 
GEOLOGICAL DistRIBUTION: Unknown. 
Ecotocy: In Tomahawk Lake, Wisconsin, this species is very 
abundant, the shore after storms being literally paved with dead shells. 
It lives on the- sandy or pebbly shores, in water from a few inches to 
several feet in depth. By wading along the beach thousands may be 
collected. The localities in this lake are all on exposed points or in 
curved bays where the shore receives the full force of the waves. 
No specimens were found in sheltered places, where the water was 
at all stagnant. As recorded by Dr. Kirkland, for angulata, they were 
irregularly scattered over the surface, crawling over the sand, where 
a distinct track was left, or else lying half buried in the sand. The 
two different colors mentioned by Nylander as being characteristic of 
the Maine emarginata were also observed in the Tomahawk Lake speci- 
mens. 
ReMARKS: This race differs from all the other races of emar- 
ginata in its very globose body whorl and rounded aperture. The race 
is very variable, the variant being the spire which is elongated or de- 
pressed. Some individuals approach mighelsi but this is rare, the shell 
being usually much more globose than that race. Angulata differs in 
having a heavier shell, a much less globose body whorl, and an elon- 
gated and angulated, instead of rounded, aperture. The umbilicus is 
closed in angulata while it is usually open in wisconsinensis. The glo- 
bose form will, however, separate this race from all others. The um- 
bilical chink is usually conspicuous but may be so wide as to form 
a deep umbilicus or may be entirely closed. 
Wisconsinensis is by far the most abundant shell in Tomahawk 
Lake, Wisconsin, where, in many places, it forms windrows of dead 
shells on the shore after a northwesterly storm. It was at first thought 
to be a variety of the mighelsi type of shell, but the globular form of 
the body whorl is so different from mighelsi and the shells are so 
numerous in the original locality as to render it quite as sags to re- 
ceive a name as are any of the races of Lymnza. 
Galba emarginata canadensis (Sowb.). Plate XLIV, figures 
19-23; plate XLV, figures 1-20. 
Limnea canadensis Sows., Conch. Icon., XVIII, Limn., sp. 45, pl. 7, figs. 
45 a, a, 1872 (not a, b, as stated on plate) —Datt, Alaska Moll., p. 69, 1905. 
Limnea emarginata DEKay, Zool. N. Y., p. 73, pl. 4, fig. 77, 1843 (part).— 
?Kennicott, Trans. Ill. State Ag. Soc., I, p. 595, 1855——HENDERSON, Nautilus, 
XX, p. 98, 1907. 
Lymn@a emarginata Linstey, Amer. Journ. Sci., XLVIII, p. 282, 1845.— 
Lewis, Proc. Phil. Acad., pp. 18, 19, 1860; Amer. Journ. Conch., VI, p. 86, 
