ROSCOMMON, 70 m. W. of Dublin, is the assize town.--Ancient Castle stood several sieges in Elizabeth's reign and in the Civil wars; now an extensive mass of ruins. See the once august ruins of the ancient Abbey, founded by Cathal Crowdeargh O'Connor, king of Connaught, in the 13th century, whose tomb may be traced in its solemn aisle. Little remains except some shattered windows and ruined arcades. Near to the modern mansion of Castle Coote are some remains of the old Castle, erected by Sir Charles Coote in the reign of James the First. It stood two sieges during the Civil wars, but is at present a mere mass of ruins; forming, however, a picturesque object in the demesne. See elegant mansion at Castlereagh; and a curious battlemented house, called Donamon Castle, may be visited from Roscommon. Its appearance is extremely whimsical, being square with projecting turrets at the angles. A lofty range of stone steps leads up to a circular doorway, nearly as high as the roof; and within is a similar range leading to the upper apartments. It is in good repair and habitable. In front is the river Suck. About 7 m. N.E. of Roscommon, the tourist may visit the picturesque but not very lofty or extensive ruins of the Abbey of Clonthuskart, in such a state of dilapidation that little more can be accurately traced than the principal chapel, the eastern window of which must once have been extremely grand. Kilmaine is the demesne of the Crofton family, within whose bounds is the hill of Kilmaine, on the summit of which is a small ancient Ch., partly in ruins. The place is solemn and fitted for meditation, were not the visitor's attention completely engaged by the very extensive prospect which bursts upon him over no less than sixteen counties. MINERALS. Nothing remarkable yet discovered. BOTANY. _Aristolochia Clematitis_, Climbing Birthwort:--in the woods of Briole near Athlone. _Cyclamen europæum_, Sowbread:--near Mount Talbot. SLIGO. Nearly half the outline of this county is maritime. Very mountainous, especially in the Coolavin district, where the Curlew Hills offer their virgin bosoms to the mineralogist. The ox mountain (Sliebh Dham) with a long train of desolate hills extends from the boggy maritime plains of Tyreragh; whilst the rough mountain land, from Lough Gilly, stretching eastward, is marked by the lofty eminences of Samore and Benbulb. Much lake and river scenery. Bounded S. by Mayo; W. by Atlantic Ocean; N. by Leitrim; and E. by Roscommon.