or COLERAIN, a county of Ireland, in the province of Ulster. It is bounded on the south and south-west by the county of Tyrone; by Antrim on the east, from which it is parted by the river Bann: by Donegal on the west; and that country and the Deucalcedonian ocean on the north. Its length is about 32½ miles, its breadth 25, containing about 511,688 acres. In 1813 it contained 186,000 inhabitants. The bogs and heaths of this county are manured with sea-shells, as those of Donegal. Like that, too, it is pretty champagne, and not unfruitful. It is particularly noted for a very clear river called the Bann, abounding with salmon, a fish said to delight in limpid streams. This river, to distinguish it from a lesser of the same name, is called the Greater or Lower Bann. In order to cultivate, settle, and civilize this county, King James I. granted it by letters patent, to a society, by the name of the Governor and Assistants at London of the new plantation of Ulster in the realm of Ireland. It contains four baronies; and besides the two knights of the shire, sends to parliament one member for the city of Londonderry, and one for Colerain. See LONDONDERRY, SUPPLEMENT.