The new species Calvitimela austrochilenis Fryday and Tephromela superba Fryday are described: the former from several collections from southern Chile and one from Marion Island, and the latter from southern South America (including the Falkland Islands), Campbell Island, (New Zealand), and Antarctica. Four new combinations are also made in Tephromela: T. atrocaesia (Nyl. ex Cromb.) Fryday from Îles Kerguelen, Heard Island, South Georgia, and southern South America; T. atroviolacea (Flot.) Fryday from southern South America and Îles Kerguelen; T. lirellina (Darb.) Fryday from only southern South America; and T. skottsbergii (Darb.) Fryday, which is shown to be an earlier name for T. austrolitoralis (Zahlbr.) Kalb & Elix, from throughout the region. Lectotypes are selected for Lecanora atrocaesia and L. atroviolacea. The systematic placement of Tephromela eatonii (Cromb.) Hertel from Kerguelen, Marion Island and Bouvetøya is also discussed but the species is retained in Tephromela.