164 Proceedings of the Royal Irish Academy. 



the broadest part of the Ardboline or Lissadill promontoiy at the foot 

 of Benbulben. Pour miles from the northern shore of this promontory- 

 land re-appears in the small flat island of Inishmurray and adjacent 

 rocks.',' 



(p. 27.) — '^^ Raised Beaches. — Portions of the coast of Druraclrff 

 Bay, not far from Carney, are marked on the map as raised beaches ; 

 these containing oysters, clams, periwinkles, &c., are now four or six 

 or seven feet above high -water mark." 



Memoir Geolog. Survey of Ireland, Sheet 55 (1885). A certain 

 portion of the description refers to the arms of the sea, Ballysadare, 

 and Sligo Bays. (JS'o available particulars given.) 



Memoir Geolog. Survey of Ireland, Sheet 54 and south-west part 

 of 42 (1880). The district described lies almost altogether in the 

 Co. Sligo. (jS'o available particulars given.) 



Memoir Geolog. Survey of Ireland, Sheets 39, 40, 51, 52, and 

 northern portion of 62 (1881). The area described occupies the 

 north-western portion of the County Mayo. It is bounded on the 

 north and west by the Atlantic Ocean, and on the south by Blacksod 

 and TuUaghan Bays." 



(p. 7.) — '^'^ North-eastern Portion of District. — The tract of country 

 to be described is that which extends from Benmore Head, west of 

 Bunatrahir Bay, to the old coast-guard station at Porturlin. 



" The physical features of this district are characterized by a bold 

 and precipitous coast-line. To the mighty roll of the waters of the 

 Atlantic must be attributed the varying features of headland and bay, 

 precipice and shingle ritlge, island and gorge, which give this coast its 

 great interest to the geologist. The ocean waves, acting along lines 

 of weakness and displacement, those of fissures, Jointage planes 

 or dykes, interesting rocks of different degrees of hardness, and in 

 various stratigraphical positions, have carved out the diverse features 

 of the coast-line, as we now find them. Eastward the greatest eleva- 

 tion attained by the cliffs is at Keady Point, where it reaches 352 

 feet from this on either side, the shore-line, while still precipitous, 

 gradually diminishes in elevation. Between Glengloss Point and 

 Belderg Harbour the cliffs range up to 189 feet high, and are sharply 

 indented along lines of fault or of fissure. To the westward they 

 again increase considerably in altitude, attaining 640 feet at Benwee 

 Geevraun Point, and in continuation of Glinsk mountain to about 850 



