Myeloconis P. M. McCarthy & Elix gen. nov. is described from the Neotropics and the eastern Paleotropics. Four new species, M. erumpens, M. fecunda, M. guyanenis and M. parva, are recognized. The genus is characterized by a medulla containing previously unknown yellow or orange pigments and perithecioid ascomata with a dark, dense, almost pseudostromatal wall, a basally anastomosing, but otherwise free, hamathecium, uniformly thin-walled asci and elongate, muriform ascospores. While its affinities are uncertain, the ascomata and their contents suggest a rather close relationship with Porina Müll. Arg. and ClathroporinaMüll. Arg. (Trichotheliaceae).