Demoulia is a genus of sea snails, marine gastropod mollusks in the family Nassariidae, the Nassa mud snails or dog whelks.
[1] The ovate-globose shell is covered with a downy epidermis.
The spire is short, conical with a papillary apex.
The outer lip is contracted, thickened externally and plicated internally.
[2] Species within the genus Demoulia include: