As I am working on the octopus Eledone cirrhosa, I can't get everything strait from dissecting the specimen I have. So I check everything I see with comparing it to papers about specific components of the octopus. Regarding the beak and the muscles controlling the beak I found two excellent papers that gave me a lot of certainty about the structures I saw. So here 3 iterations of the beak and its muscles: one with only the beak, one with the muscles but as much as possible real coloration and one with false colors to make it easier to distinguish the different muscles and their attachment to the beak.