Procalpurnus lacteus is a species of sea snail, a marine gastropod mollusk in the family Ovulidae, the ovulids, cowry allies or false cowries.
Procalpurnus lacteus have a white shell and red striped foot. This species feeding on soft corals genus Sinularia or Lobophytum. Can seen them only at night, crawling on the surface of the soft coral. During the day, they apparently hide effectively under or around the soft coral colony.
Similar to Procalpurnus semistriatus. The siphon on Procalpurnus semistriatus is solid yellowish tan colour with a distinct red-brown margin, while that of Procalpurnus lacteus is brown spotted with white.
Specimens of the two different species can sometimes be found together on a single soft coral colony.