At first when I loked into my usual websites for lichen I didn't encountered a reference to a Ramalina sp. with holes in the thallus. However, the morfological characteristics of this specimen are very similar to the pictures I saw for R. canariensis, an european species. Looking for further information, finally I found a (working?) document (available here) with a key for the genus, where mention to the holes in the thallus is explicit, moreover the holes permit to see the soredia in vesicles. This was the confirmation I needed since, on the other hand, all the chemical tests (K, C and KC) were negative. I apologize for the bad quality of the photos attached, but are the only ones I have.