Figure 2 from: Ziegler A, Seidl B (2012) Electron microscopic and preparative methods for the analysis of isopod cuticle. ZooKeys 176: 73-85. https://doi.org/10.3897/zookeys.176.2294

Figure 2 - STEM micrographs of non-decalcified tergites of Porcellio scaber. A Overview showing the mineralised exocuticle (ex) and endocuticle en and the unmineralised membranous layer (ml). The pore canals (arrows) are mineralised. B, C Exocuticle and epicuticle (ep). Approximately 25 nm thick fibres in the distal exocuticle (dex) and approximately 6 nm thick fibrils in the proximal exocuticle (pex). Pore canals arrows contain mineral. The inner epicuticle (iep) appears partly mineralised, and the outer epicuticle (oep) unmineralised, except epicuticular pore canals (epc). D, E Endocuticle with mineralised pore canal (arrow). Approximately 6 nm thick chitin-protein fibrils (black arrowheads) individually surrounded by mineral forming a twisted plywood structure. F, G Single mineral rods (white arrowheads) at the border between membranous layer and endocuticle.