A very fine, wholly septate internal mould developed on both sides, which resembles the holotype very closely. It has been selected in preference to the holotype as it shows something of the involute and densely ribbed inner whorls which are not visible on the holotype. It shows the fading out of the bulate primary ribs, followed during the next 1/4 whorl by fading of the secondaries on the flanks, and then on to the venter, with the final 1/2 whorl relatively smooth and showing the sutures in good relief and detail. From England, UK.
Size: 101 mm diameter
Size: 101 mm diameter