Elliptio congaraea (Lea, 1831) 

1. Cape Fear River, Duplin Co., NC - 83 mm
2. Rock Fish Creek, Duplin/Pender Co., NC - 54 mm
3. Tar River, Edgecombe Co., NC - 80 mm
4-6. Tar River, Nash Co., NC - 4: 70 mm; 5: 80 mm; 6: 48 mm

Type locality: Congaree River, South Carolina.

Range: Chowan to Ogeechee River systems.

Remarks: The type of congaraea is a high-beaked, crassidens-like form (similar to #2 above). These may be found in the Cape Fear and Cooper-Santee systems. The concept of congaraea has been extended to encompass complanata-like forms as well, across a much-wider geographic range. Two species may be involved. It is locally common, particularly in the Tar River.

This species differs from complanata in the usually white nacre, yellowish ground color, thicker hinge, and rays (at least as a juvenile).