Lori,
The land snails found in your potted plants are:
 
1:  round one - Polygyra cereolus (Muhlfeld, 1816) (not 1818 as listed
everywhere else, a fellow named Bank gave a compelling arguement that this
paper was actually published in 1816)  Polygyridae.  This species is
commonly transported in horticulture and sod.  It's congener, P.
septemvolva Say, 1818, is a possibility, but chances are it's cereolus.
The only way to tell them apart is by the shape of the umbilicus and even
then some populations are difficult.  The umbilicus of cereolus is tubular,
that of septemvolva is funicular (funnel shaped, broadly open at base of
shell).  Internal structures in shell as mentioned by Pilsbry are useless.
Damage to plant- minimal if any.
 
2:  probably Allopeas gracilis (Hutton, 1834).  Very commonly found in
potted plants.  There are several other options though, i.e. Lamellaxis
micra (Orbigny, 1835), don't think so, no hint of axial riblets, but some
specimens don't have them anyway, the diagnostic character is usually the
proportional size and shape of the aperture; Lamellaxis clavulinus (Potiez
& Michaud, 1838), but the apex doesn't look bulbous enough; even a large
Opeas pyrgula Schmacker & Boettger, 1891, but the shell seems to be too
tumid in the lower whorls; Subulina octona (Bruguiere, 1792), but the apex
doesn't seem bulbous enough and I can't see if the columella is truncated
at the basal end.  Damage to plant - minimal if any.
 
Kurt
 
At 09:01 AM 5/13/99 -0400, you wrote:
>Dear Conch-L,
>
>Recently I discovered two very small shells in two of my
>houseplants.  One  plant I have had for 10-12 yrs. and
>never saw any land snails.  The second plant was
>purchased last fall at a "Grand Opening Sale."  I have
>scanned them and I am hoping someone out there can give
>me some information.
>
>Lori Schroeder
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>Attachment Converted: "C:\Eudora\Attach\LandSnail.jpg"
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