A volume of accounts, memoranda, etc., 1764-1794, in the autograph of the Rev. Owen Jones (d. [at Beaumaris] 18 January 1795), rector of Newborough, 1747-1793, and Llaneilian, Anglesey, 1793-1795, with some additional entries to 1817 by his daughter, Catherine Jones [Brondeg, Beaumaris]. Also in the volume is a calendar of events, family and otherwise, 1751-1796, and a copy of the petition of William Jones, late of Hengai in the parish of Llangeinwen, Anglesey, labourer, confined in Beaumaris Gaol, 30 April 1766, to the Commissioners of HM Customs in London. Loose papers include two leaves probably from an earlier account- book, 1755-1756.

Deeds, 1490-1977, including deeds and documents mainly relating to properties on Anglesey, Caernarfonshire, Merionethshire and Middlesex, 1675-1977; and deeds relating to properties in Finchley, Middlesex, 1490-1796.

Assessments of royal aid for defraying the expense of the Navy, to be levied in the hundreds of Llifon, Talybolion, Menai, Twrcelyn, Malltraeth and Dindaethwy.

A notebook, 1809-1825, of the Rev. Peter Bailey Williams, Llanrug, containing a transcript, 1809, of Henry Rowlands's 'Antiquitates Parochiales' (pp. 1-107). The volume also contains a note (in Latin and English) concerning Mathew de Englefield, Bishop of Bangor's response to a writ of quo warranto (pp. 108-112); transcripts (in Latin and English) concerning the Merioneth Commission of the Peace for 1649 (pp. 113-119); part of a translation into English of the Statute of Rhuddlan of 1284 (pp. 121-122); 'A short account of Holyhead Church by L[ewis] Morris' (pp. 123-131); and a variety of transcripts and notes mostly concerning impropriations and other aspects of Church finances in the Dioceses of St Asaph and Bangor (pp. 132-182).
The 'Antiquitates Parochiales' was transcribed from a manuscript, apparently in the hand of Henry Rowlands, then in the possession of the Rev. J[ohn] Williams of Treffos, Anglesey (see p. 1); an additional section concerning Beaumaris, found in some manuscripts (see for instance NLW MS 115B), is not present. 'Antiquitates Parochiales' remained unpublished on Rowlands' death in 1723. The initial portions were first published in The Cambro-Briton, 2 (1820-21), 52-55 and 151-154, in an English translation by Peter Bailey Williams, possibly based on the present transcript (see the marks and marginal note on pp. 5 and 9, coinciding with the end points of the two articles), although the preamble (p. 1) differs significantly. The work was published in its entirety, in parallel Latin and English versions, in Archaeologia Cambrensis, 1 (1846), 126-135, 305-317, 389-396; 2 (1847), 6-13, 135-140, 215-222, 292-298; 3 (1848), 55-60, 164-169, 240-243, 291-301; 4 (1849), 36-44, 101-114, 176-193, 261-291. The names entered by Williams inside the covers and on pp. i-ii provide an informal, partial, index to the 'Antiquitates Parochiales'.

A composite volume, the first portion of which (pp. 1-78, old foliation 1-38), written in the early eighteenth century, contains selections from Flores poetarum, triads, englynion, the divisions of Wales (pp. 29-33), cywyddau, poems in free metre, and an incomplete table of the contents of the latter portion of the volume (pp. 57-59). The second part of the volume (pp. 79-406, old foliation 1-245 with gaps) has been neatly written in two or more hands, one of the seventeenth century and the others of the early eighteenth century. It contains Welsh poems in strict and free metres from the fifteenth to the eighteenth centuries, many of them either of Anglesey interest or written by Anglesey poets, particularly Lewis Môn, Sion Brwynog and John Griffith of Llanddyfnan.
Among miscellaneous items are copies of the Articles of Agreement between the Parliamentary Commissioners and the inhabitants of Anglesey, 1648 (pp. 295-296); Sir Edward Trevor's riddle (p. 312); and a short bardic grammar (pp. 358-362).

Deeds, relating to properties in the following counties: Anglesey, 1737-1871; Cardiganshire, 1736-1780; Carmarthenshire, 1684-1838; Caernarfonshire, 1831-1878; Denbighshire, 1591-1837; Flintshire, 1465-1855; Glamorgan, 1597-1883; Merionethshire, 1793; Pembrokeshire, 1683-1857; and Radnorshire 1623-1816.

Breviates of suits, interrogatories, deposition of witnesses and defendants' answers arising mainly from cases in the Court of the Exchequer based on complaints by Sir William Maurice against Rowland Owen, Sir Richard Bulkeley, William Williams, Sir Sackville Trevor and others concerning the title to quarries and the appropriation of millstones at Llangefni, Penmon and Vedw Vawr in Llangoed, Anglesey and at Maenol Bangor and Aber y Pwll in Bangor, Caernarfonshire, 1608-1609, 1619; and on the complaint of Sir Richard Bulkeley against Sir William Maurice for trespass in taking a millstone at Penmon, Anglesey, 1615. The papers state the title of the Crown to quarries and stones in North Wales and the evidence on which each of the complainants claimed his title.

A catalogue compiled by Albert Owen Evans of some of the books at Llanfaethlu rectory, Anglesey, in 1920.

Deeds relating to the Cilwendeg estate, Pembrokeshire, 1625-1883, and to the Skerries lighthouse, Anglesey.

Deeds and other documents, [16 cent.]-[19 cent.], collected by James Coleman, relating to Anglesey, Brecknockshire, Cardiganshire, Carmarthenshire, Caernarfonshire, Denbighshire, Flintshire, Glamorgan, Merionethshire, Monmouthshire, Montgomeryshire, Pembrokeshire, and Radnorshire, in Wales; and Cornwall, Cumberland, Gloucestershire, Herefordshire, Lancashire, Shropshire, and Suffolk, in England.

A transcript, possibly in the hand of J. E. Griffith, of a work by William Williams, Llandygai, entitled 'Cursory Remarks on the ancient and present state of the county or Island of Anglesey'. A note in pencil reads 'Written by Wm Wms of Llandegai from 1800-6'. The original manuscript from which the transcript was made appears to have been similar to, but not identical with, NLW MS 822C, which is dated 1807.
This is followed by a transcript of ['Mona Antiqua'] 'Tyn-Trefoel or Dindryfal' and 'Cadmarth' by H[ugh] Prichard, Dinam, from Archaeologia Cambrensis, 1871, pp. 300-310;, some account of Treveilir, Llowarch ap Bran, Porthamel Isa now Plas Coch, and the family of [Henblas, Llangristiolus], etc.; copies of the following wills: Thos Ellis, Portynllaen, Caernarvonshire, 1704, William Williams of Brondanw, Merioneth, 1779, Moris Lloyd of Plas Bach, Cerrigceinwen, Anglesey, 1647, and Richard Maddock of Richmond Hill [Llanfair-is-gaer], Caernarvonshire (d. 1827), the administration of Lewis Meredydd, Cae Mawr, Llangeinwen, 1699, and the nuncupative will of Wm Glynne of Elernion, Caernarvonshire, 1695 (original at Plas Brereton); and a copy of 'Sir John Bodvel a ballad written by the Late Mr Jno. Vaughan Lloyd Rector of Hope, Flintshire'.

Fourteen day-books, 1880-1891, of Hugh Parry Jones of Llannerch-y-medd, co. Anglesey, doctor and a member of the famous family of Anglesey bone-setters, containing names of patients and details of medicine prescribed.

Extracts from the diary of William Bulkeley of Brynddu, Anglesey, for the period 1734-51, transcribed by J. E. Griffith and published in Transactions of the Anglesey Antiquarian Society, 1931; a list of officers of the Anglesey Hunt, 1757-1889; notes on the Free Grammar School of Beaumaris; notes on deeds relating to Chwibren and extracts from Llansadwrn, [Anglesey] parish registers, 1612-1798.

Extracts from the diary of William Bulkeley of Brynddu, Anglesey, for the period 1734-60, transcribed by J. E. Griffith and published in Transactions of the Anglesey Antiquarian Society, 1931; list of High Constables of Anglesey for 1718; rates of wages of servants, etc., in Anglesey, 1718; and an account of the offerings received by the parson of Llanfechell, July 1734-July 1736.

Deeds and documents, mostly relating to cos Ang. and Mer. Several items relate to the Lloyd family of Dduallt, Ffestiniog, co. Mer., 1551-1740. The collection also includes overseer's accounts and other parochial records relating to the parish of Llandyfrydog, co. Ang., 1828-1869.

Deeds acquired by E. Williams of Hove, relating to premises in Brecknockshire, 1564-1823; Cardiganshire, 1663-1778; Carmarthenshire, 1437-1790; Caernarfonshire, 1437-1822; Denbighshire, 1507-1743; Flintshire, 1469-1761; Glamorgan, 1612-1775; Merionethshire, 1616-1762; Monmouthshire, 1491-1795; Montgomeryshire, 1636-1773; Pembrokeshire, 1645-1797; and Radnorshire and Herefordshire, 1543-1786.

The contents of the file include a study of bird life on Tregaron Bog (Cors Caron); a bird list for Bardsey with other notes on the island's plants, animal life, human habitation, agriculture, place names and a list of items required for the newly established observatory; birds and plants of Morfa Harlech; observations from a harrier hide at Tregaron; polecats in Cardiganshire; brief notes on cottage industry and bird life of Anglesey; visits to upland sites, mainly Cardiganshire, briefly noting plants and birds; detailed observations of wildlife and scenery during a visit to Switzerland and draft for 'A Welsh Nature Note' article (deleted).

Research papers of the botanist Richard Henry Roberts, [1953]-[2002], a county recorder for the Botanical Society of the British Isles. The papers including field notes on plants in Anglesey, together with a copy of The flowering plant and ferns of Anglesey (Cardiff, 1982) by him and heavily annotated, and offprints of articles relating to his research.

Deeds, 1507-[1839], mainly relating to Flintshire, and to a lesser extent to Denbighshire and Anglesey.