Hall and Whitfield (1873) named four species of stromatoporoids from the Upper Devonian of north-central Iowa. Their descriptions and illustrations were of external characteristics that are no longer regarded as diagnostic for species determinations. The species are here redescribed and reillustrated in thin section. Stromatopora expansa is a species of Actinostroma, and Stromatopora (Caenostroma) solidula is a species of Clathrocoilona. Stromatopora (Caenostroma) incrustans is retained in Stromatopora, and Caunopora planulata is a junior synonym of S. incrustans.--Modified journal abstract.