| |
Mesomphix
inornatus (Say, 1821)
plain button
Family
Zonitidae
Order Stylommatophora
The plain
button is one of the larger snails commonly found in leaf
litter in the forests of western Pennsylvania, sometimes near
logs or rocks. To call this snail “plain” is a
bit misleading - the somewhat glossy shell is a rather pretty
pale yellow, pale green or gold, giving away its location
to searchers.
The
shell of the plain button is heliciform, 7-12mm in diameter
and 8-10mm tall (Pilsbry,
1946). It has a thin lip, like others of its
family, and a tiny “pinhole” umbilicus. Under
magnification the shell is seen to be covered with neat
rows of minute papillae. These papillae can be used to
separate this species from a close congener, the smooth
button (Mesomphix perlaevis
Pilsbry, 1900), which has a coarser microsculpture with grooved
ridges (click here for an image of the microsculpture).
The soft body of the animal is very dark above and gray beneath.
The
plain button appears to tolerate a variety of leaf litter
habitats, as it is often found in oak litter, which is relatively
acidic. It tends to be smaller in the northern part of its
range (Pilsbry,
1946), which runs from Kentucky to New England
(Hubricht,
1985).
Ken Hotopp,
10/8/05
|
|
Development
of this
