Early Miocene; Extinct.
Original Description (from Dall, 1900, p. 1109):
"Oligocene marl of the Chipola River, Florida; Burns.
Shell ovate, moderately inflated, with about thirty-eight ribs, nine anterior with minute spines on the anterior side of each rib near the margin; sixteen medial, low and rounded, with narrower channelled interspaces; thirteen posterior, low and obliquely flattened, with their highest part on the posterior side, the last three or four bearing minute spiny pustules; beaks low, pointed, smooth, margin crenulate, serrate above behind; hinge normal. Lon. 27, alt. 23.5, diam. 10 mm.
This species is notably shorter and with fewer ribs than the forms preceding, and is especially notable for the small number of anterior ribs and the very sparse muricate sculpture."
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