Hi David. Out of interest, why do you say that is rock grayling? To me, not seeing the size, of course, it ticks all the boxes for woodland grayling, which flies in the Spanish Pyrenees and lower down on the Spanish side. I'm not suggesting you're wrong - just interested to know how you know.
The one you show is almost identical to this one, from the Val d'Aran:
I know that particular population is
fagi both because I found a dead one, so could examine the upperside, and because a local entomologist had taken and dissected one.
This next one is rock grayling (I believe), from just south of the Val, in Aragón:
My permission to net only extended to the Val d'Aran, so I couldn't catch any of these to get a glimpse of the upperside and cannot be certain. Apart from size, one of the things I look at is the eyebrow on the forewing underside. In
fagi, the dark above the eye runs straight across. In
hermione it curves up, often leaving a little orange, making an 'eyebrow' form. I've tested this against the books and it's not 100% constant across the range of the species, but it is at least a statistical difference.
Guy