Leucosyrinx subgrundifera is a species of sea snail, a marine gastropod mollusk in the family Pseudomelatomidae, the turrids.
The length of the shell varies between 20 mm and 34 mm.
The sharp keel is bent away from the spire and is bent instead towards the siphonal canal.
This marine species occurs off North Carolina to Florida, USA, and off Yucatán, Mexico.
