Argo Navis is an enormous southern constellation, representing Argos, the ship of Jason and the Argonauts, listed by Ptolemy among his original 48. It was divided, in the eighteenth century by Nicolaus Lacaille, into Carina (the keel), Puppis (the stern), and Vela (the sails). There was no reassignment of Bayer names when this took place so that, for example, Puppis lacks stars labeled Alpha, Beta, and Gamma.