LLANTHOYSAINT (LLAN-Y-DDEUSANT), a parish, in the union of LLANDOVERY, lower division of the hundred of PERVETH, county of CARMARTHEN, SOUTH WALES, 6 miles (E.) from Llangadock; comprising the hamlets of BnSawdde with Mass-y-Fynaoa, and Quarter Mawr with Gwydre, and containing 942 inhabitants. This place is beautifully situated in the soutb-eastern part of the county, on the confines of Brecknockshire, front which it is separated by the chain of hills called the Black Mosul:am. It comprises 11,140 acres, of which. 2800 are cultivated, and 4208 uninclosed mountainous land, over which the inhabitants have a. right of pasturage and turbaey. The surrounding scenery is strikingly diversified, combining features of picturesque and rural beauty with objects of bold and romantic grandeun That part oE the Black Mountain which is within the parish. forms the lofti-. est elevation in the county; and near the base of its ofsummit, called the Van, or ‘‘ Beacon," is a beautifully clear and transparent water, in the form of a parallelogram, nearly a mile in length, and about sixteen fathomsdeep,. The *esti° gran dew of the precipitate rocks that impend over the lake, and the wild character of the surrounding objects,, give to this extensive sheet. of wides a mak. ingly romantic appearance, finely contrasted with the scenery by which the lower grounds in the vicinity are distinguished. Though its situation is so elevated that the mow remains unnielted upon its border for the greater part of the year, yet its waters aboard with trout of superior quality, and with eels of extraordinary size. The river Sawdde has its source in the lake, and, after traversing the parish, falls into the Towy, near Llangadock; and the source of the Usk, also, is not far from the lake, which river forms the boundary between this parish and the county of Brecon, and after running by Trecastle, Breoon, and Usk, falls into the Bristol Channel below Newport. A fair is annually held in the village on the 10th of October. The hying is annexed to the vicarage of Llangadock: the tithes have been commuted for a rent-charge of £180, of which £80 are paid to the Bishop of St. David's, £40 to the Prebendary of Llanvynydd, and £60 to the vicar. The church, dedicated to St. Simon and St. Jude, is inconveniently situated at the eastern extremity of the parish, at the foot of the Black Mountain: according to tradition it formerly stood at a place called Twynflan or Twyallannan (church mount), about a mile from which, on a farm named Pant- bowel, was a barn, lately taken down, which is supposed to have been a chapel of ease. There is a meeting-house for Calvinistic Methodists, who have also five. Sunday schools, in which 620 males and females are taught gratuitously; and there is a day school, in which 60 children are instructed at the expense of their parents.