The new species Miriquidica effigurata, M. squamulosa and Pertusaria stellata are described from the southern subpolar region from collections made by Henry Imshaug and co-workers in the early 1970s. All three species occur on Campbell Island, New Zealand, with M. effigurata and P. stellata also occurring on the Auckland Islands, New Zealand, and P. stellata also being reported from Isla Desolación in southern Chile. Miriquidica effigurata and M. squamulosa are similar to M. complanata but have apothecia with a dark (K+ purple-red) lower hypothecium and thalli containing confluentic acid and norstictic acid respectively. Pertusaria stellata is similar to P. macloviana, but has shorter ascospores and a smoother, generally paler thallus lacking papillate isidia. Cephalodia are reported for the first time in both Miriquidica and Pertusaria.