This Scaphopod is from the Pliocene Yorktown Formation, Rushmere Member. Found in some matrix from the inside of a large Ecphora from the Tar River in Edgecombe County, North Carolina. One resource I have at home (NCFC volume 2, Fossil Molluscs) calls this Polyschides thallus while every online resource I can find online calls it Cadulus thallus. I cannot find any resource showing a change in Genus from Cadulus to Polyschides. Does anyone have a resource showing this? Which one is correct?