Fig. (5) Dirina massiliensis growing on a marble capital of S. Fosca church (Torcello, Venice) (A) and on frescoes of Villa Rossi (Gattaiola, Tuscany) (B). (C) Thin section, cross polarized light, showing the large amount of calcium oxalate formed and deposited outside fungal hyphae (in blue). (D) Cross section showing the lichen thallus and large bundle of hyphae (in blue) penetrating into the substrate.