The new lichenicolous fungus, Clypeococcum lenae, growing on Solorina is described from the Siberian Arctic. The species is characterized by immersed, aggregated pseudothecia, united by a common, K+ violet clypeus, and often laterally and basally surrounded by stromatically transformed host tissues, I and K/I− hymenium, well-developed pseudoparaphyses, bitunicate, 8-spored, I and K/I− asci, and brown, ellipsoid to obovate, muriform ascospores. A key to the species of lichenicolous fungi that grow on Solorina is provided.