Figure 2.Arctomia borbonica (holotype). A–B macroscopic view of the thallus, with details of the wrinkled surface B and soredioid margin, made of disintegrating goniocysts C–D cross section through the thallus, showing the cortex with small, isodiametric cells, and the Nostoc chains E surface view of the cortex F young goniocysts formed at the lobes margins. Scale: A–B = 1 mm; C–E = 20 µm.