Notes on Iowa Diatoms IV. : The Diatoms in a Northwest Iowa Fen

The physical features of a fen are discussed including chemical and physical analyses of the water. Diatom samples were taken during the summer of 1962 and a list of 48 species distributed among 20 genera was compiled. A series of photomicrographs of some of the species is presented. Ecological and floristic differences between cold and warm pools are discussed and a comparison with the diatom flora of the Cabin Creek Raised Bog in Indiana (published by C. W. Reimer) is made