Resupinate Basidiomycetes from Costa Rica. Rare and new species of Atractiellales (Auriculariales s.l.), Exidiaceae, Sirobasidiaceae and Tremellaceae

Species of Atractiellales (Auriculariaceae s.l.), Exidaceae, Sirobasidaceae and Tremellaceae are reported as new for Costa Rica or as new to science. Tremella coalescens L.S. Olive, Sirobasidium minutum Kisim., Oberw. & Gomez sp. nov, Hererochaete vitrea Kisim.. Oberw. & Gomez sp. nov., Exidiopsis m ucedinea (Pat,) K.Wells, Helicogloea aurea Baker, Saccoblastia sphaerospora Moller and Occultifur internus (L.S. Olive) Oberw. All the new species are described and illustrated. Since the original material collected in Brazil by Moller is lost, a neotype for Saccoblastia sphaerospora Moller is propo sed. This Costa Rican collection represents the first record since the disc overy of the species in 1891. Hyphoderma argillaceum (Bres.) Donk is report ed for the first time from Costa Rica as the fungal host of Occultifur inte rnus.