A manuscript containing a Welsh grammar. A note in the hand of Moses Williams reads: 'This copy is out of a MS. lent me by R. Mostyn of Penbedw Esqr., which MS. formerly belong'd to Thomas ap Ivan of Hendre Forfydd [i.e. Peniarth MS 157]. Twas compared with the said MS. 29 Julii 1717 ... Twas also collated with another copy that was once in the possession of Huw ab Owen alias Huw Machno.' There are notes by Moses Williams on the text throughout the volume.