DERRALOSSORY, or DERRYLOSSORY, a parish, partly in the barony of NEWCASTLE, but chiefly in that of BALLYNACOR, county of WICKLOW, and province of LEINSTER, 9 miles (N. W.) from Wicklow; containing 4412 inhabitants.

This parish, which is situated in the mountain district of Glendalough, and on the road from Dublin, by way of the Seven Churches, to Rathdrum, is intersected by the river Avonmore, and comprises 54,865 statute acres, as applotted under the tithe act, and valued at £5894 per ann. A very considerable portion is rough mountain, affording tolerable pasturage for sheep and cattle; about 700 acres are woodland, and 16,000 good arable and pasture land; the quantity of waste and bog has been greatly reduced.

The military road also passes through the parish. The soil is various, and the system of agriculture improved; the principal crops are potatoes and oats, the cultivation of which has been gradually extended far up the mountains. In the vale of the Avonmore, and in the more western mountains, are large tracts of bog, of which those in the lower grounds have been nearly cut out for fuel.

At Glendascene are some very extensive lead mines, worked by the Irish Mining Company, and affording employment to 180 persons. Though generally characterised by dreariness of aspect, the heights in some parts present features of grandeur and sublimity; and extensive plantations have been made on several of the demesnes, which materially improve the scenery of the parish.

The principal seats are Derrybane, the residence of W. Truelock Bookey, Esq., situated in a tastefully disposed demesne under the hill of the same name, which is richly clothed with timber, and commands a fine view of the picturesque vales of Clara and Glendalough, with the distant mountains, and containing within the grounds the venerable remains of the ancient abbey church of Glendalough; Roundwood Park, the seat of J. Gower, Esq.; Castle Kevin, of -- Frizell, Esq., M.D., who has planted with rich and ornamental timber the various hills around the demesne, commanding extensive views of Lough Dan and the wild scenery of that neighbourhood; Lake Park, the admired residence of Gerard Macklin, Esq., situated on the side of Carrigroe, formerly a wild and barren spot, which has been reclaimed and formed into a handsome demesne commanding fine views of Lough Dan and the adjacent mountains; Dromeen, of Capt. Hugo, which, in the disturbances of 1798, was partly destroyed by the insurgents, who were repulsed with great loss by a detachment of military sent for its protection; Glenwood, of H. Grattan, Esq., who is now erecting a school-house in the demesne, and has covered the hills on his property with thriving plantations; and Cronybyrne, of L. Byrne, Esq. Fairs are held at Togher on Jan. 3rd, for cattle, March 8th, for frieze, and 14th, for cattle, May 19th, July 26th, Aug. 1st, Sept, 5th and 19th, Nov. 8th, and Dec. 5th, for frieze.

The living, though denominated a perpetual curacy, is endowed with the rectorial tithes; it is in the diocese of Dublin and Glendalough, and in the patronage of the Archbishop of Dublin. The tithes amount to £456. 10. The glebe-house, which is situated close to the village of Annamoe, was built by aid of a gift of £250 and a loan of £550 from the late Board of First Fruits, in 1816, together with a considerable sum from the incumbent.

The glebe comprises 60 acres, of which 20 are barren and unprofitable land. The church, situated in a wild and uncultivated tract between Roundwood and Annamoe, and remote from any dwelling, was enlarged in 1820, by aid of a loan of £450 from the same Board, together with large contributions from the parishioners. In the R. C. divisions the parish is called Glendalough, and is co-extensive with that of the Established Church; there arc chapels at Roundwood and Annamoe.

The parochial school at Raheen is supported by subscription, and there is a national school at Glendalough; in these about 100 children are instructed, and there are also two pay schools, in which are about 80 children.

At Castle Kevin are the ruins of the old castle of the O'Tooles, which was reduced by Cromwell, between whom and the royalists a battle took place also at the ford over the river, between this place and the Seven Churches.