1. Lake Monroe of St Johns River, Volusia Co., FL - 100 mm
2. Econlackhatchee River, Seminole Co., FL - 92 mm
3. Econlockhatchee River, Seminole Co., FL - 77 mm
4. St Johns River, Seminole/Volusia Co., FL - 74 mm
Elliptio websterii (Wright, 1888)
1. Lake Monroe of St Johns River, Volusia Co., FL - 100 mm
2. Econlackhatchee River, Seminole Co., FL - 92 mm
3. Econlockhatchee River, Seminole Co., FL - 77 mm
4. St Johns River, Seminole/Volusia Co., FL - 74 mm
Type locality: Lake Woodruff, St Johns River, Volusia Co., Florida.
Range: Endemic to the St Johns River system.
Remarks: This large and distinctive species is virtually unknown to most malacologists, attesting to its apparent rarity. It is closely related to marsupiobesa, and is placed with the Crassidens Group because of its angled posterior slope and propensity to form radiating wrinkles there as well. The nacre is usually white, light purple in some specimens.
Unio hartwrightii Wright, 1896, is a synonym.