Amastra aemulator

The length of the shell attains 15.5 mm, its diameter 8.6 mm.

(Original description) The shell contains seven whorls. The shell is narrowly perforate, ovate-pyramidal, and moderately solid. The spire's outlines are nearly straight at the base, becoming slightly concave near the apex. The whorls are slightly convex and relatively short. The 2½ whorls of the protoconch are a dull purplish color and very finely and regularly striate when unworn. The subsequent whorls are irregularly wrinkle-striate, with the cuticle initially light olive, transitioning to olive-brown on the last two whorls. The surface is somewhat glossy, but where the cuticle is worn away, it reveals a dull gray and purplish-brown calcareous layer beneath.

The aperture is small, slightly oblique, and dull purplish-gray inside, becoming paler with a barely perceptible thickening near the lip. The columella is short, thick, and whitish, featuring a subhorizontal lamella. The parietal callus is very thick, its edge forming a ledge that seamlessly connects the ends of the lip.^[2]

This species is endemic to Hawaii and occurs on Oahu Island.

• Cowie, R. H., Evenhuis, N. L. & Christensen, C. C. (1995). Catalog of the native land and freshwater molluscs of the Hawaiian Islands. vi. Leiden: Backhuys Publishers. p. 107.{{cite book}}: CS1 maint: multiple names: authors list (link)