Rafinesquina ponderosa, showing left to right the interior pedicle valve, the exterior pedicle valve, and the interior brachial valve. This genus was named after Constantine Samuel Rafinesque (1783-1840), a naturalist who worked for many years at Transylvania University in Lexington, Kentucky.
Source: Pope, J.K and W.D. Martin. 1979. Field Guidebook to the Biostratigraphy and Paleoenvironments of the Cincinnatian Series of Southeastern Indiana. Seventh Annual Field Conference of the Great Lakes Section, Society of Economica Paleontologists and Mineralogists. Miami University Audio Visual Service: Oxford, Ohio.