Early Miocene; Extinct.
Original Description (from Dall, 1900, p. 1020):
"Oligocene of the Chipola River, Calhoun County, Florida.
Shell small, thin, inequilateral, anterior end longer, more convex, and evenly rounded; posterior end shorter, rather suddenly pointed, and slightly flexed; beaks pointed, smooth, prominent; lunule and escutcheon obsolete; disk without radial striae, but with very thin, regular, rather distant concentric, elevated lamellae, easily worn off, the posterior end with an obsolete radial fold; hinge normal, pallial sinus large, gibbous, nearly reaching the anterior adductor scar, more than half confluent below. Lon. 13.5, alt. 8.5, diam. 4 mm.
Much more delicate and of a different form from the preceding species."
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