Antiplanes thalaea is a species of sea snail, a marine gastropod mollusk in the family Pseudomelatomidae,.

(Original description) The solid, heavy shell has an elongate spire constricted at the sutures, and eight or more whorls.

The surface is covered with a pale apple green periostracum, which fades in time to a greenish gray.

The outer lip shows a deep anal sinuosity, leaving a slightly depressed fasciole behind it.

The anterior part of the outer lip is much produced and rounded, thin and simple.