A manuscript containing the Welsh Laws, being a transcript of British Museum MS Harleian Titus D. II. Three folios at the beginning and two at the end contain poetry in Welsh and Latin, etc. There are also some items of a corn account.
The general style of the handwriting, which is not all in the same hand, is suggestive of the manuscripts of Dr John Davies, Mallwyd, which were copied partly by him and partly on his behalf.

A composite volume containing lists of Welsh words and their meanings, some in the autograph of John Jones ('Myrddin Fardd'), others from printed sources; notes in the autograph of R. Prys Morris, including references to a number of 'cywyddau', etc. by Edmwnd Prys in BM Add MSS and a few extracts from [Joseph] Besse, A collection of the sufferings of the people called Quakers (London, 1753); part of a letter from the Reverend Evan Evans [? Llansadwrn Rectory, Anglesey] to 'Myrddin Fardd'; and transcripts in the autograph of 'Myrddin Fardd' and others of poetry by Rowland Jones, Richard Hughes, Cefn Llanfair, Cadwaladr Cesail, Thomas Williams ('Twm Pedrog'), Morys Dwyfech, Huw Arwystl, [ ] 'Gutto o Leyn' (d. 1867) (beginning wanting) and [Evan Pritchard] 'Ieuan Lleyn', some printed in J. Jones ['Myrddin Fardd'], Cynfeirdd Lleyn (Pwllheli, 1905).

A transcript, 1750, by 'William Owen o Gonwy yn Sir Gaernarfon ...' of 'cywyddau' and 'englynion' by Lewis Morris, John Roger, Hugh Hughes, Dafydd ap Gwilym, Wiliam Cynwal, Sion Tudur, William Sion, Owen Gruffydd, Michael Prichard, Hwmffre Dafydd ab Ifan, Wiliam ap Huw Llŷn, Huw Morus, Robert Humphreys ('Robin Rhagad'), Sion Rhydderch, Sion Dafydd Lâs, Ellis Rowland, Wiliam Phylip, Dafydd Manuel, John Vaughan (Caergai) and 'Thomas Llwyd Ifangc'.

'Y Llyfr hir or Mwythig', being a collection of five hundred and sixty-six cywyddau, etc. by various authors arranged into 'books' according to subject. The poems in each 'book' are numbered separately. The poets cited include Iolo Goch, Dafydd ap Gwilym, Siôn Cent, Iorwerth Fynglwyd, Bedo Brwynllys and Siôn Phylip. The volume is dated temp. James II (see p. 382). The text is followed by nine folios of index, arranged under authors' names, by Richard Morris. Following the index are three further poems (by Dafydd ap Gwilym, Siôn Cent and Dafydd ab Edmwnt) in the hand of the Reverend Samuel Williams.
The volume is in the same hand as Llanstephan MSS 47, 48 and the end of 164.

A volume consisting almost entirely of Parts I - II of 'Y Piser Hir' in the hand of Owen Williams, Waunfawr, Caernarvonshire, being transcripts, with copious annotations, made during the period 1859-60, of 'cywyddau', 'awdlau', 'englynion', etc. by Tudur Aled, Gruffydd ab yr Ynad Coch, Guto'r Glyn, Sion Tudur, Edmund Prys, William Llyn, Simwnt Vychan, Gruffydd Hiraethog, Sion Brwynog, Dafydd ab Edmund, Iolo Goch, Gwerfil Mechain, Ieuan Gethin ab Ieuan ab Lleision, Gwilym ab Ieuan hen, Dafydd Nanmor, Owain Gwynedd, Aneurin Wawdrydd, Dafydd Llwyd ysgolaig, Dafydd Llwyd ab Llywelyn ab Gruffydd, Dafydd Meifod, Dafydd ab Meredydd ab Tudur, Dafydd ab Hywel, Dafydd Ddu o Hiraddug, Edward Morys, Edward Maelor, Ellis Rowlands, Gruffydd Llwyd ab Dafydd ab Einion, Gutyn Ceiriog, Gwilym ab Sefnyn, Gruffydd Philip, Hugh Morys, Huw Arwystl, Hywel Dafydd ab Evan ab Rhys, Huw Llwyd Cynfel, Huw Gruffydd ('y Quaker'), Hywel ab Syr Mathew, Huw Cae Llwyd, Huw Roberts ('o Dre Logen'), Ieuan Llwyd Siephrey, Ifan ab Hywel ab Swrdwal, Llawdden Brydydd, Ieuan ab Rhydderch, Lewis Mon, Llywelyn ab Gutyn, Meredydd ab Rhys, Morys Dwyfech (Morys ab Ifan ab Einion), Owain ab Llywelyn ab y Moel, Ffoulk Prys, Owain Deiliwr, Prydydd hael, Richard Philip, Robin y prydydd bach, Robert ab Rhys Wyn, Rowland Vaughan, Rhys Goch Glyn Ceiriog, Robin Ddu Ddewin, Rhys Goch Glyn Dyfrdwy, Robin Cludro, Rhees ab Hary ('gwr boneddig or Dref hir yn Euas'), Rhys ab Hywel ab Dafydd, Sion Philip, Dr Sion Cent, John Prichard, John Davies ('Sion Dafydd las', 'Bardd Meirion'), John Gruffydd (Llanddyfnan), Sion Mawddwy, Syr Dafydd Trefor, Siancyn ab Einion, Sion Roger, Tudur Penllyn, Thomas ab Robert, Thomas Prys (Plas Iolyn), William Philip, Elis Cadwaladr, Huw ab Evan ab Robert, Dafydd ab Gwilym, Sion Risiart, John Davies [? Rhiwlas], Gruffydd Grug, Lewis Daron, Lewis Glyn Cothi, Llywelyn Guto Banwr, Dafydd Epynt, Llywelyn Goch ab Meirig hen ('o Nanau'), Rhys Penardd, Edward ab Rhys, Rhys Nanmor ('pencerdd'), Gruffydd ab Dafydd Vychan, Llywelyn ab Gruffydd ab Ednyfed, Robin Ddu o Fon, Syr Huw Pennant, Dafydd Gorlech, Gruffydd ab Llywelyn Vychan, Ieuan brydydd hir, Ieuan Gruffydd Leiaf, Ieuan Dyfi, Olifer ab Daf'dd Llwyd, Llywelyn ab owain ab Cynwrig Moel, Rhys D'dd Llwyd ab Einon Lygliw, Llywelyn ab Ednyfed leiaf, Dafydd ab Rhys, Rhys Goch Eryri, Meredydd Llwyd, Llywelyn ab Hywel ab Ieuan ab Goronwy, Ll'n ab Einion Ddu, Hwlcyn, Llywelyn ab Hywel, Syr Rhys [o Garno], Owain Dwna, Robin Ddu o Arfon, Gr'dd ab Ieu'n ab Ll'n Vychan, Syr Ieuan, Syr Owain ab Gwilym, Gruffydd ab Goronwy Gethin, Dafydd ab Llywelyn Fychan, etc. The text also includes 'Casbethau Ieuan Brydydd hen' and some Nanmor and Llandrillo pedigrees, and a lacuna in the text of one 'cywydd' is completed in the hand of [John John Roberts] ('Iolo Caernarfon'). Part I is based on 'Llyfr Brith Corsygedol' (Peniarth MS 198) and Part II on a manuscript probably in the hand of John Jones, Gellilyfdy. There are imperfect lists of contents at the beginning of each part. Bound in at the end of the volume, also in the hand of Owen Williams, are 'englynion' ('I'r Iesu', etc.) transcribed in 1853 from a manuscript (1655) of William Salesbury of Bachymbyd; two versions of an address on 'Helynt y Cymry, eu hiaith a'u defodau, etc.' delivered at Eisteddfod Tywyn, Tre Fadog, and prepared for publication in the Carnarvon Herald; and a biography of Richard Jones ('Gwyndaf Eryri'; 1785-1848). The volume is lettered on the spine in gold: 'Owain Gwyrfai MS'.

A transcript, 1874-1876, by Ioan Pedr of some of the poetry contained in NLW MS 642B.