Here are a couple more steinkerns from the Cretaceous sediments of Delaware. As I mentioned in previous posts, these are clay casts of the interior space of Pelecypod shells.
This is a cast from a Neithia shell and could be Neithea quincostata
This cast is very likely Liopistha protexta
Both specimens come from the C and D canal in Delaware and were collected from spoil piles left over from dredging efforts. Their age is late Cretaceous (Campanian to Maastrichtian stages).
Thanks to John's site Fossils of New Jersey for helping me ID these fossils.
Another sites with an extensive collection of fossils from the canal is Dr. Fossil's site about the "Deep Cut"