Elliptio occulta (Lea, 1843)

1. Sand Lake, Seminole Co., FL - 58 mm
2. Oklawaha River, Marion Co., FL - 56 mm
3. Wekiva River, Lake/Seminole Co., FL - 45 mm
4. Alexander Spring Creek, Lake Co., FL - 49 mm

Type locality: Black Creek, Florida.

Range: Alafia, Oklawaha, St Johns, and Wekiva River systems.

Remarks: This species may be recognized by its compressed shape, winged posterior, sharp posterior ridge, dark posterior slope, polished surface, and (usually) rays. The periostracum may be iridescent in some specimens.

A peculiar color form from Alexander Spring Creek is yellow (#4).

Unio fuscata Lea, 1843, has page priority over Unio occultus Lea, 1843, but the former is a junior homonym of Unio fulvus variety fuscata Rafinesque, 1831.

Unio maywebbae Wright, 1934, is a synonym.