Late Pliocene to Early Pleistocene; Extinct.
Southern Florida to Virginia.
Original Description (from Conrad, 1833, p. 341):
"Shell sinistral; with strong concentric undulated laminae transversely striated; superior valve flat; inner margin crenulated. Found with the preceding species."
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- Early Pleistocene
- Caloosahatchee Formation (S. FL)
- Nashua Formation (N. FL)
- Waccamaw Formation (SC, NC)
- Late Pliocene
- Duplin Formation (NC)
- Jackson Bluff Formation (N. FL)
- Raysor Formation (SC)
- Tamiami Formation (Lower) (S. FL)
- Tamiami Formation (Pinecrest Beds) (S. FL)
- Yorktown Formation (VA)
- Yorktown Formation (Moore House Member) (VA)