Width 2.6 mm; 5 1/2 whorls; with about 55 riblets on body whorl, apical 1 1/2 whorls smooth.
Umbilicus narrow, about 1/6 width of shell; base flattened and with reduced riblets, except for outer third; 4 palatal lamellae visible through base of shell, 1 and 3 short, 2 and 4 longer; without palatal lamellae above periphery; large parietal tooth extending to margin of parietal callus; infra-parietal and inter-parietal callus not visible in this image.
Spire low conic, with obtuse-rounded summit; periphery bluntly angular; base flattened below the periphery; riblets oblique.
Notes - Locality Missouri, St. Louis Co., Rockwoods Reservation, on half decayed logs [38° 33' 46"N, 90° 38' 48"W ]; found with S. labyrinthica; abundant.