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Ron Lutz II |
Vitrina
angelicae Beck, 1837
Eastern glass-snail
Family
Vitrinidae
Order Stylommatophora
Small
and fragile, the eastern glass-snail is unusual in its shape
and habits. A nearly transparent shell, whose body whorl opens
widely, seems barely large enough to cover the snail’s
soft body as it withdraws. This snail is often found in damp
grassy habitats near wetlands, streams and rivers, sometimes
beneath wood, or among rocks. They may be found in apparently
dry habitats that are wet during other parts of the year.
The shell
of the eastern glass-snail is 6mm wide and 4.5mm tall, described
by Gould (in Pilsbry,
1946) as “globose-discoid” with the
last whorl “much expanded.” The shell is shiny,
thin and fragile, and is clear or pale green. The umbilicus
is tiny. This animal is distributed in Europe, Canada, and
the northern United States to the Midwest. In Pennsylvania
it is found in the north and west (Hubricht,
1985).
The
eastern glass-snail seems contrary in its habits – it
is a northern species that is only active and breeding late
in the year, rather than in the warmer months as most land
snails. It is apparently an annual, not found alive in spring
and summer. George Clapp reported that this species was among
river drift along the Ohio River near Pittsburgh, and large
numbers were seen in October and November when the temperature
was between 1.7º and 7.2ºC (35º and 45 ºF;
(in Pilsbry,
1946). Clapp observed them laying eggs in bunches
of six or eight beneath wood debris.
Ken Hotopp,
10/17/05
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