Asthelys simplex is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.

The base of the shell is covered by about fourteen rounded ridges and furrows, which are rather stronger toward the center, the last one, forming the edge of the umbilicus, being specially so.

Color: The surface is a dead slightly creamy white, formed by a thin calcareous layer through which the underlying nacre shines.

The outer lip is sharp and thin, not patulous, not descending, advancing at its junction with the body whorl, then retreating so as to form the broad open sinus, acute angled at the periphery, slightly arched across the base, nicked close to the point of the pillar.

From the body whorl it bends very much over to the left, so as largely to cover the umbilicus, and then it curves over to the right to join the outer lip on the base at an obtuse angle.