Salkehatchie River, Hampton/Colleton Co., SC - 1: 72 mm; 2: 68 mm; 3: 74 mm; 4: 71 mm
Elliptio gemina (Lea, 1856)
Salkehatchie River, Hampton/Colleton Co., SC - 1: 72 mm; 2: 68 mm; 3: 74 mm; 4: 71 mm
Type locality: Buckhead Creek, Burke Co., Georgia.
Range: Salkehatchie, Savannah, and Ogeechee River systems.
Remarks: This rare species apparently has a very narrow range. It is quite unlike any other species in the area, but most similar to conferta, which occurs just to the north. The easiest way to tell it from conferta is the size of the adductor muscle scars, which are 1/3 to 1/2 smaller in gemina than in a similar sized conferta. The periostracum is shaggier in gemina than in conferta, with closely spaced growth lines. The nacre of gemina is purple or white; the nacre of conferta is nearly always white or gray.
Unio hepaticus Lea, 1859, described from the Salkehatchie River, is a synonym. The illustrated specimens are topotypes of hepaticus.