Late Pliocene to Early Pleistocene; Extinct.
Northern Florida to Virginia.
Original Description (from Conrad, 1839, p. 51):
"Shell oblique, ovate, ventricose, rounded at base and posterior extremity; ribs about 36, subtriangular, narrow, prominent; posterior margin very long, oblique and subrectilinear; umbo narrow, summit very prominent; margin profoundly crenate. Length 4 inches; height 4.5 inches. Locality, Yorktown, Va."
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