Antarctic muscicolous leprarioid lichens are examined chemically and morphologically. The species belong to Lepraria, Lecidella and Lecanora. Crocynia nivea Hue, C. candidadissima Hue and Lepraria angardianaovstedal are placed in synonymy with Lepraria caerulescens (Hue) Botnen &ovstedal comb. nov. (syn. Crocynia caerulescens Hue), and the species is lectotypifled. Lepraria arctica (Lynge) Wetmore is reported for the first time from the Antarctic and the southern hemisphere. Some non-leprose taxa are also discussed.