SUMMARYMycelia ofAthelia epiphylla, A. decipiens, A. neuhoffii, A. borealis, A. bombycina, andA. bicolorgrowing in vitro were analyzed for fatty-acid composition by GLC and TLC methods. The major fatty acid in each fungus was a diunsaturated 18-carbon acid with lesser amounts of 16: 0, 18: 0, and 18: 1. An unidentified 18: 2 was detected inA. bicolor.The fungi could be identified by their fatty-acid patterns.