UPDATE (2020-10-18): So I changed the name on this fossil, I think this is a Paraconularia missouriensis (Swallow, 1860) which is found in this Indiana county. The ridges are alternating when matching up at the midline thus a Paraconularia (Sinclair, 1940). I originally posted it as being Conularia (Miller, 1818). See this 2016 posting:
Learn more about this type of fossil at Dr. Mark Wilson's posting on the Wooster Geologist site:
A note about Conularia, it was originally shown (see above) on plate XX figure 7 in The History of Rutherglen and East-Kilbride by David Ure (1749-1798), Glasgow:Printed by David Niven 1793. The specimen was not named but the author writes this on pages 330-331. "The clafs to which the curious foffil, fig. 7. pl. XX. originally beloned, is not fo far as I know, determined. The fpecimens are in cafts of iron-ftone, fometimes found incolfed in iron-ftone like a nucleus ; at other times found among till along with marin fhells, &c. Specimens are very rare." Note their typesetting back this strange to me. It looks like the the substitute lowercase f for lowercase s on some words. Find a scan of the book at: https://www.google.com/books/edition/The_History_of_Rutherglen_and_East_Kilbr/0jgtAAAAYAAJ?hl=en&gbpv=0
References:
Miller, Hugh 1818. The Mineral Conchology of Great Britain by James Sowerby, Volume III, p. 108
Sinclair, G.W. 1940. A discussion of the genus Metaconularia with descriptions of new species. Transactions of the Royal Society of Canada, 34:101-121
Sinclair, G. W. 1952. A classification of the Conulariida. Fieldiana Geology, 10:135–145.
Swallow, G. C. 1860. Descriptions of new fossils from the Carboniferous and Devonian rocks of Missouri. Academy of Sciences of Saint Louis, Transactions, 1:635–660.