The Barddas of Iolo Morganwg, Vol. I., ed. by J. Williams Ab Ithel, , at sacred-texts.com
The above Alphabets are from Llywelyn Sion. *
p. 74 p. 75
Abcedilros; so were called the ten primary letters, because they are put in one word of four syllables, being arranged according to the word, thus,
A. B. C. E. D. I. L. R. O. S.
After that M and N were invented, and thence there were twelve letters, which were called Mabcednilros, the letters being thus arranged--
M. A. B. C. E. D. N. I. L. R. O. S.
making twelve letters. After that four other letters were devised, namely, G. T. P. F. And then there was a new arrangement of the letters; all that were partially co-vocal being placed next to each other, as if of one family in respect of sound. That is to say, firstly, the simple ones, namely,
A. E. I. O.
Then the labials, namely, M. B. P. F.
Then the dentals, namely, D. T. N.
Then the palatals, G. C.
Then the non congeners, namely, L. R. S.
And thus were they arranged,--
A. E. I. O. B. M. P. F. D. T. N. G. C. L. R. S.
and were called after their primitive name Abcedilros, though the authentic letters might, in respect of kind and number, be more than what are found in the special word.
After that, two other letters were devised, namely or , and or , then there were eighteen letters. After that, two others, which made twenty, namely, and . After that, four other letters, namely, . . ; 1 which were arranged on the Coelbren according to their families in respect of sound and vocalness, and mutual relation. After that secondary letters were devised, which are . . . , &c., as far as thirty-eight. Still their old
designation is retained, which is, Abcedilros. An old Book calls them, Abcednilroswm.
73:* p. 72 This statement is made by the copyist, Iolo Morganwg.
75:1 p. 74 A letter, probably either or , ought to be supplied here, in order to make up the number four, if that, and not three, was really intended.