Shell strong, white, planorboid in shape, with a maximum diameter of 5.5 mm. (0,25 inch), widely and deeply umbilicate. Number of whorls 3. Spire flat with slightly depressed apex and with slightly rounded whorls. Periphery of shell squarish. Axial sculpture in earlier whorls consists of closely spaced, rather sharp, raised ribs which are more developed on the periphery of the whorl than on the top of the whorls. These ribs become obsolete on the last half of the last whorl. Spiral sculpture consists of 8 strong cords on the periphery of the whorls. Wherever they cross one of the axial ribs, a large rounded tubercle is produced. The center cord on the middle of the periphery becomes obsolete, or nearly so in the last whorl. Umbilicus widely open, very deep, and bearing fine, sharp, axial ribs which are especially well-developed in the earlier whorls. There is a weak, crenulated, spiral cord running into the umbilicus. Interior of aperture circular, opaque white. Peristome round with the peripheral edges at the top and bottom produced into a tubercle. Suture well-indented, partially obscured by the tubercle of the former whorls. These tubercles are often hollowed out on their anterior surface. The entire exterior shell is covered with minute, axial, crowded threads which give a "frosted" appearance. Operculum and animal unknown. Height 2.5 mm; Max. diam. 5.0 mm; Min. diam 4.0 mm Range. Off Palm Beach and south to Tortugas, Florida.