A
Length, 2.3 mm; color transulent to opaque white; surface with fine growth striae and dull from very minute granules; angular and parietal lamellae straignt, forming bilobed crest; columellar lamella small and tubercular.
B
Upper margin of peristome not extending beyond body whorl; peristome receeding toward base.
C
Lip thin, no crest behind lip
D
Variation: Crawford Co., MO.; with small upper palatal tooth.
Notes:
A-C, Washington Co., Hwy 47 at Mineral Fork crossing, 11 mi N of Potosi;
D, Crawford Co., MO, Hwy E at Huzzah
Creek, 2 mi S of Onondaga Cave State Park.
Variation: upper palatal tooth in Crawford Co. lot varies from distinct (as illustrated above) to absent.
References:
Pilsbry, 1948, LMNA pp. 804, fig. 480 1-4
Hubricht, 1985, Dist. Nat. Land. Moll. E. US, p.
9, map 53