FIGURE 9 in Morphology and taxonomy of Isognomon spathulatus (Reeve, 1858), a cryptic bivalve from the mangroves of Thailand

FIGURE 9. Mantle morphology of Isognomon spathulatus (A, B: Histology, 5-µm, PAS stain; AMNH 319258; 52 mm; D: SEM; AMNH 319258; 55 mm). A—Cross-section of the mantle margin; B—Cross-section of the mantle margin at the centralto-contractile zone transition region; C—Fragment from the ventral part of mantle showing the inner surface with distinct central, contractile, and marginal zones; D—Laterodorsal view of the mantle edge with a fragment of OF-2 removed to reveal OF-1 (SEM). Abbreviations: ce, columnar epithelium; cpa, circumpallial artery; cpn, circumpallial nerve; ec, eosinophilic cell; if-n, inner mantle fold; mfb, muscle fiber; mlc, contractile zone of mantle lobe; mlh, homogeneous central zone of mantle lobe; mm, mantle margin; of-n, outer mantle fold; p, periostracum; pgr, periostracal groove; pm, pallial muscle; t, tentacle. Scale bars: A, B: 200 Μm; C: 2 mm; D: 500 Μm.