Christopher Barker's Device

I have often been puzzled to understand the precise meaning of the inscription on Christopher Barker's device. Whether this arises from my own ignorance, or from any essential difficulty in it, I cannot tell; but I should be glad of an explanation. I copy from a folio edition of the Geneva Bible, "imprinted at London by Christopher Barker, printer to the Queene's Majesty, 1578." The device consists of a boar's head rising from a mural crown, with a scroll proceeding from its mouth, and embracing a lamb in the lowest fold. The inscription on this scroll is as follows:— "Tigre . Reo. Animale . D…