Vallonia pulchella on a penney.
Width 2.4 mm; 3 1/2 whorls; shell somewhat transparent, with a milky tint; upper surface finely and irregularly striate; apical 1 1/2 whorls smooth, with faint and week longitudinal striae near margins; peristome distinctly and abruptly expanding, and thickened within.
Umbilicus about 1/4 of shell width, much enlarged in last 1/2 turn.
Aperture forming 5/6 of a circle.
Spire convexly curved; last whorl not descending in front; aperture oblique.
Notes - locality Missouri, Montgomery Co., Bluffton, near intersection of Hwy 94 and Katy Trail, in soil along bluffs. Differs from V. excentrica by the distinctly and abruptly expanding lip (best viewed from above).