Amastra umbilicata was a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Amastridae.

The peristome is simple and acute, with the columellar margin slightly dilated and entirely free throughout, adding to the shell's delicate and refined appearance.

This species differs from Amastra petricola in several key features: it has a larger umbilicus, a thinner, unicolored shell, a more slender spire, and a smaller, more oblique columellar fold.

Unlike A. petricola, the specimens examined show no sign of thickening within the outer lip, suggesting the two species are not closely related.

The columellar margin is triangularly dilated and bears a small, highly oblique fold, which emerges more prominently than that of A. petricola, extending nearly to the edge.