A rarely collected myxomycete, Comatricha mirabilis, developed on five collections of bark of large shrubs from the desert in the Kingdom of Bahrain. The distinctive morphology of this specimen is identical or very similar to that of specimens previously known from goat droppings in the USA (Illinois, Holotype), straw (England) and an unreported substrate in France. The spore and capillitium of the new specimens are compared to those from USA and England with light and scanning electron micrographs. The new collections are considered in the light of the previously known distribution of this taxon and other species. Comatricha mirabilis is suggested to be a myxomycete that is more common in certain arid habitats than previously recognized.