I believe this is a Devonian Period brachiopod called Cyrtina found in the Jeffersonville Limestone.  They were found in Jefferson County, ...

These pictures are of pieces of the echinoid Archaeocidaris from the Mississippian Period. They were found in the St. Benevieve Formation of...

Some images of a Modiomorpha clam fossil found in the Mahantango Formation, Pennsylvania. This pelecypod existed in the Devonian Period. ...