Shell moderately small (less than 3 mm) and transparent. Shell walls relatively strong and thick, with a faint yellowish or pink hue. Keel moderately elevated and rounded, without a truncate leading edge. Keel base generally brownish. Shell surface smooth. Spire somewhat elevated and rounded, with shallow sutures. Eyes type a, with lenses of average size (distinctly smaller than in adult A. lesueuri of comparable size). Radula small, ribbon-like. Lateral teeth monocuspid or with a very small accessory cusp. Although difficult, young specimens of Atlanta oligogyra can be distinguished from young Atlanta lesueuri by the slightly lower and rounded spire, with a shallow suture. Confusion about the validity of this species arose after Tesch (1949) combined it with Atlanta lesueuri, thus reversing his previous position (1906) when he recognized the two species as distinct. Richter (1974, 1986) showed that Tesch was correct in his 1906 paper and that Atlanta oligogyra is a valid species.
See the family Atlantidae for a discussion of the species groups.