Fig. 3. Scanning electron micrographs of the setae found on the lateral and medial flagella of Palinurus elephas. The lateral flagellum (A-D) has an aesthetasc tuft, which is flicked through the water. The medial flagellum (E-F) remains stationary during the flick. Distal is towards the left of the page in images A-E. (A) The lateral region of the aesthetasc tuft shows the aesthetascs (ae), which form paired rows on each annulus (an) of the flagellum. A single guard hair (g) per annulus flanks both medial and lateral edges of the aesthetasc tuft. Paired simple companion hairs (sc) only are located on the lateral side of the aesthetasc tuft. Scale bar, 0.5 mm. (B) Paired plumose companion hairs (pc) are found only on the medial region of the aesthetasc tuft. Scale bar, 0.5 mm. (C) The ventro-lateral side of the lateral flagellum shows the positions of setae along the aesthetasc tuft. The asymmetric setae (as) are found on the lateral side of the aesthetasc tuft just proximal to the guard hairs (g). Scale bar, 0.5 mm. (D) The lateral region of the aesthetasc tuft is shown with guard hairs and companion hairs removed so that the paired arrangement of aesthetasc rows per annulus is visible. Scale bar, 0.5 mm. (E) Long plumose setae extend along the medial flagellum. Scale bar, 0.5 mm. (F) Each plumose hair on the medial flagellum has an array of setules extending along its axis. Scale bar, 0.01 mm.