Myxogastromycetidae is a subcategory of amoeboid protists. There are 421 species of Myxogastromycetidae, in 17 genera and 3 families. It includes groups like Physariida.
Definition: A group of species that exploit the same food resources, and/or use the same feeding or foraging methods. http://en.wikipedia.org/wiki/Guild_(ecology)