Buccinanops cochlidium, common name the gradated bullia, is a species of sea snail, a marine gastropod mollusk in the family Nassariidae, the Nassa mud snails or dog whelks.

It is of a reddish yellow color, scattered over with longitudinal flames of a brown red.

The aperture is ovate, whitish, and strongly emarginated at its base.

This handsome species is particularly remarkable by the turreted whorls, and above all by an original deposit of whiter calcareous matter, which is seen at the upper part of the lower whorls of the shell.

[2] This marine species occurs from Central Brazil to Argentina