(d'Orbigny, 1836)
Diagnosis: Blunt spire highly coiled, more than 6 colorless whorls. Thicker parts of shell near aperture brownish, smooth except for faint growth lines. Conspicuous suture sometimes light-brown. Thickened inner aperture chestnut-brown. Umbilicus very small. Small rostrum more pointed in older than in young specimens. Protrusions on anterior wing border absent. Embryonic shell with rough ornamentation of irregularly ramified flat ridges (Boltovskoy, 1974b). Shell height 2 mm, diameter 1.4 mm.