Colsyrnola brunnea is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.

The 2½ whorls of the protoconch are small and polished, and have a depressed helicoid shape.

The sixteen whorls of the teleoconch are flattened, slightly shouldered, and rather low between the sutures.

They are marked only by lines of growth and microscopic spiral striae.

It bears a strong oblique fold a little anterior to its insertion.