Arcania is an attractive butterfly, bright orange when fresh, and quite common and widely distributed in southern France although I don't often find it in good numbers. However, in the Alpine regions I was checking each “pearly” closely in case it was the much rarer Darwin's Heath (C. darwiniana.

I have placed the more detailed comparison of the relative features of arcania, darwiniana, and Alpine Heath (C. gardetta) on the darwiniana page.

observations

a typical arcania, with a clear light band on the unf and, unusually, two ocelli. The unh ocelli are quite strong in s2/3, strong black with clear white centres, medium in s4 and small in s1 and s5, with a creamy post-discal band. The marginal silver band is strong and complete, more visible in the enlarged versions below. The s6 ocellus looks as if it could be considered as "contained within" the light post-discal band.

a female, based on the visible body shape. No ocellus in s1.