Figure 15 in Refining molluscan characters: morphology, character coding and a phylogeny of the Caenogastropoda

Figure 15. Midgut morphology. White arrows indicate direction of ciliary currents. (A) Bithynia tentaculata, dorsal view. Distal end of gastric chamber obscured in scanning electron micrograph, indicated by dotted line in diagram on right. (B) Littorina littorea, dorsal view. Stippling indicates ciliary tract within gastric chamber extending from oesophageal aperture. Scale bar = 1 mm. Abbreviations: c, caecum; ce, caecal extension; cf, ciliated fold; cs, ciliated strip; ctr, ciliary tract; dgd, digestive gland duct; e, oesophagus; gp, glandular pad; gs, gastric shield; sa, sorting area; ss, style sac; t1, major typhlosole; t2, minor typhlosole.