Amastra montagui

The length of the shell attains 13 mm, its diameter 7.8 mm.

(Original description) Amastra montagui is a sinistral, imperforate, relatively thin oblong-conic shell. It is chestnut-colored with a denuded ecru-olive patch in front of the aperture. The surface exhibits a subtle silky sheen due to the presence of fine growth wrinkles.

The apex is obtuse, and the whorls of the protoconch are convex and nearly smooth. The spire displays noticeably convex outlines, with a well-impressed suture accentuating the slightly swollen appearance of the whorls just below it.

The aperture is moderately oblique and slate-violet on the interior. The peristome is black-edged and reinforced internally by a faint white callus. The columella features a reflexed and adnate edge adorned with a prominent, white, subtriangular lamella.^[2]

This species is endemic to Hawaii, occurring 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. pp. 1–248.{{cite book}}: CS1 maint: multiple names: authors list (link)