Cucullaea gigantea pelecypod from the Aquia Formation

I recently traded with a fellow in my local club for these two Cucullaea gigantea from Henson Creek, Maryland. They come from the Aquia Formation (Paleocene age). It earns its name as these casts are really huge! I've read about the site where these can be found but just have not been able to get down there to collect some myself.

Specimen #1

Specimen #2