Mynyddyslwyn

The name of the parish Mynyddyslwyn, in Monmouthshire. This name, so full of Druidic suggestion, was lost from general use at, and anterior to, the incorporation of Wales with England by the statute of Rhudolan. In a list of the names of Welsh parishes at that time, the parish is called *The Parish of Tudor ab Howell*. Has any reader of the "NOTES AND QUERIES" met with Mynyddyslwyn in any document bearing an earlier date?