Pilsbryspira aterrima is a species of sea snail, a marine gastropod mollusk in the family Pseudomelatomidae.

The shell has a very dark chocolate color, with sometimes a narrow white line above the periphery, but this is usually absent.

Below the keel are a few raised revolving lines, occasionally broken up into granules.

The great variation in the proportions of this shell has caused a number of synonyms to be made.

[2] This species occurs in the Pacific Ocean from Mazatlan, Mexico to Northern Peru