Thallus crustose, thin, often filmy, smooth or rarely ± verrucose, effuse. Photobiont green ?. Ascocarps orbicular, red-brown to black, ± pellucid when wet, with a persistent, often slightly raised, proper margin, thalline margin absent. Excipulum proprium and thecium characteristically composed of a continuous, loose network of anastomosing paraphysoids in a common gelatinous matrix. Asci cylindrical-clavate to ovate, apices markedly thickened, 2- to 8-spored. Ascospores colourless, transversely septate to densely muriform. Pycnidia unknown.