Copyright © The Classical Association 2014. The expression pelle Libystidis ursae, which occurs at Aen. 5.37 and 8.368, has caused a certain amount of puzzlement among scholars. This article will attempt to explain, through Virgil's allusions to Apollonius' Argonautica, the function of Libystis as a pointer to the motif of the creation of a new homeland within a foreign territory, as is the case with Segesta and Rome. This idea is further developed by the two omens that forebode the foundations of Segesta and Rome, that is, the omen of Acestes' arrow at Aen. 5.522-8 and the weapon-omen at Aen. 8.524-9, both of which are consistently associated with flames, comets, and lightning. These elements underline the symbolism of destruction, rebirth, and Jupiter's will that characterizes the foundations of Segesta and future Rome.