Early Miocene; Extinct.
Original Description (from Dall, 1892, p. 309):
"Chipola beds, near Bailey's Ferry, Chipola River, Northwest Florida, Hurns.
This variety has the basal carina double as in well-developed specimens of the type, together with the equatorial spiral sculpture of T. bipertita. The lines of growth are periodically sharp and elevated, and the sides of the whorls are comparatively flat. The apical whorls are only faintly sculptured, and the nucleus is very minute. The best-preserved specimen measures 60 mm. long and has a maximum diameter of 21.5 mm. These specimens are somewhat more compact than the type, though it is quite variable in this respect."
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