There are several characteristics that seem to indicate that Lecidella is the correct choice for the genus: The asci of Lecanora type, the bluish upper hymenium, the brown exciple and the lax paraphyses are some of them. Moreover, in addition, the red-brown hypothecium intensifying in K (see the photo of the microscopy with a mount in K) seems to point to L. elaeochroma, a species that I found before with greenish thallus instead of the brown one in this specimen. At least I could not found an alternative in the British Flora. Unfortunatelly I was not able to find any mature spores.