Figure 27. – Etelis carbunculus Cuvier, 1828. Ground section. Polarised light. Black and white superimposed collagenous plies are characteristic of an orthogonal plywood-like structure. The basal plate (bp) is partially mineralized. Mandl corpuscles (arrow) are observed at the level of the front of mineralization. (micrograph: F.J. Meunier). Figure 28. – Macrourus berglax Lacepède, 1801. SEM. Broken freezed scale showing the lamellar structure of the basal plate. The direction of the collagen fibrils of adjacent layers are at right angle to one another forming an orthogonal plywood-like structure. Figure 29. – Poecilia reticulata Peters, 1859. TEM. Rapid freeze anhydrous techniques. Front of mineralization (mf) in the basal plate (bp). Figure 30. – Poecilia reticulata. TEM. Rapid freeze anhydrous techniques. The crystals are located in the spaces surrounding the cross-sectioned collagen fibrils that appear electrolucent. Figure 31. – Carassius auratus. TEM. Demineralized section. The superimposed plies of the basal plate (bp) are crossed by the TC fibres (tc) that arise from the hyposquamal scleroblasts (hs) and reach the external layer (el). ll: limiting layer Figure 32. – Carassius auratus. TEM. Rapid freeze anhydrous techniques. The characteristic aspect of the front of mineralization is due to the presence of the TC fibres (tc). It differs from the smooth one of Poecilia reticulata, which has no TC fibers (Fig. 29). Figure 33. – Poecilia reticulata. TEM. Mineralized corpuscles, Mandl corpuscles (mc), are located ahead of the front of mineralization. Figure 34. – Carassius auratus. TEM. Mandl corpuscles (mc) located ahead of the front of mineralization. Figure 35. – Trisopterus luscus. SEM. The front of mineralization is ornamented with fused Mandl corpuscles. Figure 36. – Cyprinus carpio. SEM. Mandl corpuscles and the mineralization front show a ridged surface due to the presence of TC fibres.