French travellers on scientific and trade missions to the Pacific in the early 19th century set out to add more detail to the cartography of the European explorers of the Enlightenment. In this undertaking, the island toponyms proved to be of considerable importance, in terms of political appropriation and geographical control of the territory. The apparent concern to «reproduce» indigenous names and to find adequate terms to designate and identify the islands was not devoid of contradictions. This article highlights these contradictions in an attempt to shed light on the formation and identification of a vast insular territory.