After revising the order Pertusariales in Tierra del Fuego (Messuti & Vobis 2002), Teuvo Ahti drew my attention to some nomenclatural problems concerning Pertusaria pachythallina (Räsänen) Messuti. This name was based on Pertusaria grisea var. pachythallina Räsänen. However, the new combination was invalidly published since the page of publication was not indicated (Art. 33.3, Ex 5 ICBN 2000) and the lectotypification originally performed by Lamb (in herb.) did not meet the Code requirements (Art. 7.11). The correct nomenclature and typification are indicated below.