A map of the counties of Dearborn, Ohio, Switzerland, Jefferson and Ripley showing the location of sections and collecting localities and the boundary between the Ordovician and Silurian systems
"Boundary after Foerste." Detached from: The stratigraphy and paleontology of the Cincinnati series of Indiana / E.R. Cumings. In Indiana Dept. of Geology and Natural Resources thirty-second annual report, 1907. Indianapolis: Wm. B. Burford, 1908. Page 680. Imprint: [Indianapolis] : [Indiana Dept. of Geology and Natural Resources], [1908] Dimensions: on sheet 60 x 51 cm; Scale: Approximately 1:126,720. 2 miles to the 1 inch