Ogam stones to the number of 54 exist in Great Britain, the cipher being identical with that of the Irish inscriptions. Of these South Wales has 25, Scotland 16, south-west of England 5, and the Isle of Man 6. Most of the Welsh and south-west stones have Roman lettering of a rude type which points to the early Christian period, when there was close intercourse between the Irish and Welsh Churches. One of the Welsh stones is of considerable importance, as it furnished an efficient test to the truth of the key to the cipher in the _Book of Ballymote_, and as demonstrated independently by Dr. Graves. This stone is at St. Dogmael’s, near Cardigan; it contains an Ogam inscription, and another in Roman letters. A copy of the former was sent to Dr. Graves, whose reading was practically identical with the Roman lettering which he had not seen. On a close examination of the stone, traces of the vowel _a_, which had been cut by a crack and absent in the copy of the cipher, were discovered, and the truth of his reading thus wholly verified. Besides marking burial and other sites, Ogam stones are found in all kinds of situations: in souterrains, in some fourteen of which Ogam stones have been discovered; in drains and other field uses; and in the walls of churches and other buildings. In the underground chamber of Dunloe there are seven Ogam stones; in Drumloghan, Co. Waterford, ten; and on the stones forming the roof of a drain at Ballyknock, Co. Cork, there are fifteen inscriptions. When their original use had long been forgotten, they were evidently taken from their sites and converted into such building or farm purposes as the occasion required.