Amastra rubristoma

The length of the shell attains 19.12 mm, its diameter 12 mm

The shell is dextral, imperforate, solid, and elongately ovate-conic, with an acute apex. The surface is marked by irregular growth striae, and the nuclear whorls are delicately radiately sulcated. Its coloration varies from reddish-brown to almost white, with darker upper whorls, often covered by a dark, fugacious epidermis. There are seven convex whorls with a well-impressed suture.

The aperture is slightly oblique and oval, with a red interior that occasionally appears livid-white. The peristome is acute and subtly thickened within. The columella ends in a strong, arched, lamellar plait, faintly tinged with red.^[2]

This species is endemic to Hawaii, occurring on the main island at Hilo.

• Hyatt, A. & Pilsbry, H. A. (1910–1911). Manual of conchology, structural and systematic, with illustrations of the species. Ser. 2, Pulmonata. Vol. 21: Achatinellidae (Amastrinae). Philadelphia: Conchological Department, Academy of Natural Sciences. p. 240. Retrieved 3 December 2024.{{cite book}}: CS1 maint: multiple names: authors list (link) This article incorporates text from this source, which is in the public domain.
• 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)