Amastra luctuosa


Amastra luctuosa is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Amastridae.
Subspecies: Amastra luctuosa sulphurea Ancey, 1904

Description

The length of the shell attains 16 mm, its diameter 8 mm
The shell is imperforate, dextral, oblong-conic, and solid, with fine striations and a slight sheen. It is distinctly bicolored, with a striking contrast between light and dark tones. The spire is inflated-conic, tapering to an acute apex, and the suture is finely crenulated.
There are 6 whorls, with the upper four being black and nearly flat, the penultimate whorl pale and more convex, and the body whorl comprising about two-fifths of the total shell length. The body whorl is pale tawny above and blackish below the periphery.
The aperture is slightly oblique, sinuate-semioval, and white inside. The columellar fold is laminiform, subbasal, and triangular. The peristome is unexpanded, acute, and edged in black, adding to the shell's sharp and elegant appearance.

Distribution

This species is endemic to Hawaii, occurring on Oahu island.