I excavated this from matrix that fell out of the Drum Cliff Member of the Choptank Formation in Calvert Cliffs. I have looked at all the books and online resources I have to find a species, but nothing quite matches. If anyone has a species, I'd love to hear! This is the only specimen I've ever seen, let alone found. This one, like most other shells in the matrix, is extremely fragile and would not have survived exposure to the elements long.