Fig. 4

The dorsal oikoplastic region of both species. Bathochordaeus charon (top) compared to B. stygius. The large esophagus of B. charon (a) is contrasted with the more slender and tubular esophagus of B. stygius (c). Plates B and D are magnified views of the right Fol’s oikoblast from each specimen. Both species appear to have 12 large posterior Fol’s cells (fp) with trap cells (t) just in front of them (b, d); however, the anterior row of Fol’s cells (fa) is greatly reduced in B. charon (b)