The Elliptio crassidens Group
Elliptio cirrata (Lea, 1874) - Savannah and Edisto River systems
Elliptio corvus (Lea, 1859) - Salkahatchee & Ogeechee River systems
Elliptio crassidens (Lamarck, 1819) - Mississippi River system; Gulf drainages from Leaf to Amite River systems
Elliptio dariensis (Lea, 1842) - Endemic to Altamaha River system
Elliptio downiei (Lea, 1858) - Endemic to Satilla River system
Elliptio fraterna (Lea, 1852) - Apalachicola and Savannah River systems
Elliptio incrassata (Lea, 1843) - Escambia, Choctawhatchee, Apalachicola, Chipola, and St Marys River systems
Elliptio marsupiobesa Fuller, 1972 - Endemic to the Cape Fear River system
Elliptio mcmichaeli Clench & Turner, 1965 - Escambia, Choctawhatchee, Pea, and Amite River systems
Elliptio monroensis (Lea, 1843) - Endemic to St Johns River system
Elliptio websterii (Wright, 1888) - Endemic to St Johns River system