Four species of corticolous lichenized and non-lichenized ascomycetes are described from a tropical lowland rainforest in southern Venezuela: Mycomicrothelia xanthonica Komposch, Aptroot & Hafellner along with the closely related M. macrocarpa Komposch, Aptroot & Hafellner (Arthopyreniaceae), Pseudopyrenula cryptotheca Komposch, Aptroot & Hafellner (Trypetheliaceae), and Ancistrosporella psoromica Komposch, Aptroot & Hafellner (Opegraphaceae). Descriptions and illustrations are presented and the relationships of the taxa discussed. In addition, the following new combination is proposed: Ancistrosporella curvata (Aptroot) Komposch (Opegrapha curvata Aptroot). Ancistroporella G.Thor is regarded as typographical error and corrected to Ancistrosporella.
