FIG. 15. — A in Quaternary and Recent shells of Ocenebra erinaceus (Linnaeus, 1758) and O. brevirobusta Houart, 2000 (Mollusca, Muricidae, Ocenebrinae): reflections on the intra- and interspecific variations

FIG. 15. — A, average Fourier power spectrum for the apical view, 99.95% of the power is described by the first nine harmonics, represented by the arrow; B, same for the ventral view, 99.95% of the power is described by the first 12 harmonics, represented by the arrow.