We start on sol and use sol-la-si/ti. We have two finalis: sancti ends on sol but amen ends on la. The recitation is la. Hypophrygian, I think, has recitation tone la with mi as finalis. But I cannot find the mode for this simple melody. In modern music we would say that Signum Crucis starts on Do abd end on do with amen ending on re which is not an ending tone. What mode is this?