FIGURE 7. Mactrotoma fragilis (Gmelin, 1791), A–B: hinge description by using the nomenclature developed by Bernard and Munier Chalmas, scale bar = 1 cm, A: RV, B: LV; C–E: Ultrastructure of the shell, C: general aspect of radial section of a LV from close to hinge to ventral margin scale bar = 100 µm, D: detail of the outer layer with cross lamella structure, scale bar = 50 µm, E: detail of inner layer with the cross lamellar complex, scale bar = 20 µm.