A few weeks since some manuscripts were placed in my hands belonging to the Hon. E. M. L. Mostyn, M. P. (removed from the library at Mostyn Hall in Flintshire), in order that I might ascertain the contents; and on looking at them, I discovered a play in the autograph of Anthony Mundy, with his signature at the end, and the date (supplied by another hand) of December, 1595. This play, entitled "_A Booke of John a Kent and John a Cumber_," seems to have been hitherto unknown to all the writers on the history of the stage; and its plot and dialogue appearing to me sufficiently curious to deserve publication, I lost no time in communicating my discovery to Mr. J. Payne Collier, under whose able editorship I am happy to learn that the work (by permission of Mr. Mostyn) will shortly be printed by the Shakspeare Club. The object I now have in view in making these remarks, is to point out an error relative to MUNDY (as he spells his own name) which, if not corrected, may acquire greater circulation than it possesses even at present. In Warton's _History of English Poetry_, 4to. vol. iii. p. 292. _n._ (printed in 1781), at the close of his biographical account of Mundy, he makes the following statement: "He [Mundy] collected the arms of the county of Middlesex, _lately_ transferred from Sir Simeon Stuart's library to the British Museum;" and this paragraph is copied word for word by Chalmers (writing in 1812), and inserted in his _Biographical Dictionary_ under the article MUNDAY (ANTONY). As no record exists in my department of any such transfer, I was desirous to trace the truth of this assertion, which the date of Chalmers could hardly have enabled me to do, had I not fortunately consulted Nichols's _Literary Anecdotes_, vol. viii. p. 645., where I found a letter from the Rev. Michael Tyson to Gough, dated June 10, 1777, in which he mentions the manuscripts then recently sold at the seat of Sir Simeon Stuart, in Hampshire, and adds-- "A bookseller opposite the Exchange bought an heraldical lot of eighteen volumes, big and little, for which he asks twenty guineas: among them is Hawes's [_read_ Harvey's] original _Suffolk Church Notes_, and a beautiful _Visitation of Cambridge_."