MATHREY (MERTHYR), a parish, in the union of HAVERFORDWEST, hundred of DEWISLAND, county of PEMBROKE, SOUTH WALES, 8 miles (S. W. by W.) from Fishguard; containing 1012 inhabitants. This parish, which is situated in the north-western part of the county, is bounded on the north by St. George's Channel, and is intersected by the turnpike-road leading from Fishguard to St. David's. In the northern part of the parish, bordering on the coast, which is for the most part bold and abrupt, the depth of water varying from seven to fourteen fathoms near the shore, are some considerable slate quarries, affording employment to a portion of the inhabitants. The rateable annual value of property is returned at £2418. 5. 6. The village, which is situated on the summit of a hill, was formerly a place of more importance than at present, and had a weekly market and an annual fair, granted by letters patent in the reign of Edward III.; the former has been long since discontinued, but the latter is still held on October 10th, and is numerously attended by the inhabitants of the surrounding district, for the purpose of hiring servants; and another fair takes place on November 22nd at Nevin, a village on the coast. The living is a discharged vicarage, united, together with that of St. Nicholas, to the vicarage of Granston, and rated in the king's books at £4. 7. 6., and endowed with £200 royal bounty: the rectory constitutes the Golden prebend in the Cathedral Church of St. David's, rated in the books at £25. 14. 4+., and in the patronage of the Bishop, under whom the tithes are held on lease by Sir John Owen, Bart. The church, dedicated to the Holy Martyrs, and situated in the middle of the village, is an ancient structure, but not distinguished by any architectural details of importance. About 30 children are in strutted in a day school at the expense of their parents; and a Sunday school, attended by from 30 to 50 males and females, is maintained by Mrs. Blanch M. Davies, of Carnachenwen. Tithes of the annual value of £4. 15, are stated to have been given by an unknown donor, for decayed farmers' widows of the parish, but nothing is now known of this charity. A perfect cromlech, or Druidical altar, consisting of a table stone seventeen feet in length, and apparently resting upon six upright columns, but only supported by four, is still preserved at Long House, in the village of Trevin, or Trevdyn, a manor belonging to the -Bishop of St. David's, where was once an episcopal palace, said to have been erected by Bishop Martin, to which Long House was formerly thege. The ancient mansion of the family of Iies, of Priskilly Forest, is now the property and residence of John Hill Harries, Esq. The whole of the coast exhibits vestiges of earthworks, evidently thrown up by the early piratical invaders who infested this part of the principality. Mr. Edward Llwyd communicated to the Royal Society of London an interesting account of an extraordinary swarm of locusts that visited this place in 200 1693, and of which the particulars are fully detailed in the second volume of the Philosophical Transactions.