Identified using Henry Nettelroth's Kentucky Fossils Shells book (1889) found at this site. In the book, it was identified as Rhynchonella tethys (Billings, 1860). Its modern name is Cupularostrum tethys (Billings).
This small fossil was found in the Jeffersonville Limestone of Clark County, Indiana USA. This layer would date it to the Middle Devonian Period. It is a rare find for me making two found so far.
