Oligyra orbiculata Say, 1818

globular drop

Shell globose, 5 whorls; surface with little gloss, and with very faint and scattered striae; color cinnamon, with whorls fading to white or buff at upper edges.

Shell imperforate; faint longitudinal striae sometimes visible on base.

Spire conic, whorls shallowly rounded; body whorl with cinnamon bands above and below the middle, fading to buff above to suture and below toward base; aperture is half-circle.

Peristome thickened and slightly recurved.

Peristome with forward projecting angle or blunt tooth before columella.

Operculum tear-drop shaped, upper end narrowly rounded, lower end broadly rounded; parietal edge slightly concave; surface shallowly concave with a series of concentric waves, and an elevated ridge near parietal margin, thinnest at center of concentric waves; microsculpture is network of irregular lines, with surfaces slightly elevated in between, orange-peel in appearance at lower magnification.


Notes:

Locality: Missouri, Barry Co., 2 mi N of Eagle Rock, under board and stones in glade.

 

[Pilsbry, 1948, LMNA, II(2):1082-1084]
[Hubricht, 1985, Fieldiana 1359:3, map 2]