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Fig. 8. Kinematics of the ridge. (A) Plot of the antero-posterior length of the
ridge as seen in a top view versus the antero-posterior length of the
protrusion of the ridge above a circular arc fitted to the odontophore in a
side view (r2=0.84, P<0.002).
Fig. 5 shows one frame of these
data and how they were analyzed. Lengths are measured in radular stalk width
units (RSW). (B) Area of the ridge recorded in vitro during a
dopamine-induced series of movements. See
Fig. 7B for definitions of
events labelled on the x axis. Area is reported in units of
RSW2. (C) Area of the ridge recorded in vivo from
mid-sagittal frames (sequence 7732-S3, frames 16-39). Note the large ridge
area at the end of protraction and at the onset of retraction, which
corresponds to events 4 and 5 of the in vitro data, i.e. radular
closure and odontophore elongation.