[3] The shell of the arnaudi is small, measuring approximately 13 mm in diameter.

The outer lip is rounded and exhibits lirations from the spiral ornamentation.

The whorls, cords, and lamellae are covered by regular growth lines.

The base of the rachidian teeth is curved, and there is a large, smooth marginal area.

This species is named in honor of Dr. Patrick Arnaud[5] from Marseille, France for his significant contributions to Antarctic malacological studies.