What is "vasum"

Vasum \Va"sum\, n. [L., a vase. See Vase.] (Zo["o]l.) A genus including several species of large marine gastropods having massive pyriform shells, with conspicuous folds on the columella.

Vasum, common name the vase snails or vase shells, is a genus of mostly rather large predatory sea snails, marine gastropod mollusks within the family Turbinellidae.