Fig. 11. Movements of the odontophore relative to the buccal mass. The left panels show rotation of the anterior border of I6 relative to the jaw line. The right panels show translation of the anterior tip of the odontophore relative to the jaw line, with the jaw line rotated to be vertical. (A-D) The rotation (left panels, angle as a function of time) and translation [right panels, distance, in units of internal radular stalk width (RSW units) as a function of time] during each of the four individual swallowing sequences. (E) Normalized, averaged and smoothed rotations (left) and translations (right). Data are shown as the mean ± 1 S.D. (F) Schematic diagrams indicating the rotation of the odontophore for frames 1, 9, 18 and 22. The anterior margin of the odontophore is highlighted with a black line, and the jaw line (relative to which the angle is measured) is highlighted with a gray line. The translation of the odontophore for frames 1, 9, 18 and 22 is shown on the right. A gray line highlights the jaws, and a black line indicates the distance from the anteriormost point of the odontophore to the jaw line. Compare original frames in Fig. 5. For definitions of periods t1, t2 and t4, see Materials and methods.