A stratigraphic study of the plant microfossils m the Iowa Pennsylvanian coals by the maceration method has been in progress during the past three years. A statistical correlation was made between two coal sections near what Cheer, Iowa, by the selection and use of six distinctive microfossils. Further examination of 42 samples of coal from eight Iowa counties yielded many spore types of which eight are now described as new genera and species. No serious attempt has been made to use the described spores as horizon markers
