Figure 3.

Volume rendering of a grayscale image stack based on paraffin wax sections of the phoronid Phoronis australis. (a) Original section image, Heidenhain's Azan trichrome stain (40× magnification). (b) Volume rendering based on 115 grayscale section images using the X-Radia TXM-viewer (artificial glow colormap, linear transparency function). white arrow = anus. (c) The same volume rendering as in 3 b but further trimmed. black astersisks = pores of metanephridial ducts. (d) View from the adult posterior end. white asterisks = funnel openings of metanephridia. Scale bar = 500 μm.