See list of synonyms Tritia is a genus of sea snails, marine gastropod mollusks in the family Nassariidae, the Nassa mud snails or dog whelks.

[1] (Described as Neritula) The shell is ovate, depressed, with the axis distorted.

The inner lip is callous and is spread over the body whorl.

The outer lip is reflected, not denticulate or striated.

The body whorl is depressed and extends over the penultimate whorl, nearly covering and concealing the spire, which, consequently, appears very obtuse.