Lily Lake, a subalpine lake in the Wasatch National Forest Tl5, R9E, S31, of the Uinta Mountain Region, Utah, is located about one-half mile west of Trial Lake at an elevation of 10,000 feet. This Lake, which is one of the acidic, cold, lentic bogs characteristic of this area, has been selected for a taxonomic and seasonal distribution study of acquatic phycomycetes. This study is a beginning to our knowledge of the role of the fungi in the hydrobiology of Lily Lake and will supply the first information on record of the water molds of this area. The study identifies the fungi found on fourteen types of substrata and correlates it with the environmental data of the lake.

A taxonomic and ecological survey of the algae of Lilly Lake in the Uinta Mountains, Utah, was carried on from June 1967 to November 1967. The lake is a typical acid bog lake with an average pH range of 4.5 to 6.9. Extremes of pH in the alkaline range were present due to additional factors. Algae identified included 96 genera and 208 species. These were found in many different types of microenvironmental niches. The main factors which limited the algae to definite areas of the lake were pH, water temperature, light available, and type of substrate. The predominant algal genera uresent in all parts of the lake at all times of the growing season were Scenedesmus, Pediastrum, Microcystis, Aphanocapsa, Sphaerocystis, Spirogyra, desmids, and diatoms. Algae that thrived only under cold water, acid conditions were Eunotia., Culinclrocystis, Euglena, and Chlamydomonas. Genera that grew abundantly when the pH increased to the alkaline range were Dictyosphaerium, Lepocinclis, Phacus, Synura, Pandorina, and Trachelomonas. The most dominant genus in the center stations of the lake was Chara. Fishing and resultant pollution of the marginal waters caused large, bright green blooms of Spirogyra. Algae that appeared in greatly disturbed areas were Closterium and Oscillatoria. Planktonic algae or drifters were not present floating in the water but did occur in the marginal areas where seepage provided necessary nutrients.