anciently Derg-abhan, i.e., "the river of the woody morafs," from a river which issues out of this lake. This lough is situated in the county of Donegal and province of Ulster in Ireland, and is famous for having in it the island that contains St Patrick's purgatory, which is a narrow little cell, hewn out of the solid rock, in which a man could scarce stand upright.—There is also a lake of this name situated between the counties of Galway and Tipperary.