¶1] Mag Muirthemne, whence the name? Not hard to say. The sea covered it thirty years after the Flood, and hence it is called Muirthemne, that is, darkness of the sea, or it is under the sea's roof. Or there was a magic sea over it, and an octopus therein, having a property of suction. It would suck in a man in armour till he lay at the bottom of its treasure-bag. The Dagda came with his 'mace of wrath' in his hand, and plunged it down upon the octopus, and chanted these words: Turn thy hollow head! Turn thy ravening body! Turn thy resorbent forehead! Avaunt! Begone! Then the magic sea retired with the octopus; and hence, may be, the place was called Mag Muirthemne.