Ixx INTEODUCTION 



features. Rare plants very few in number, Cardmnine amara and- 

 Polygonum mite being the only ones which come up to the standard 

 used for the other divisions. 



31. Louth. 



Eastern. Area 316 square miles. The smallest county in 

 Ireland. Maritime, with an extensive coast-line, which around 

 Dundalk Bay is the flattest in the country. The southern five- 

 sixths of the county is low and fertile, the Silurian grits being 

 deeply covered by drift. Near CoUon, on the inland border, the 

 ground rises, forming a ridge of hills of 600 to 800 feet elevation. 

 Northward, around Dundalk, the ground is exceedingly flat ; and 

 in glorious contrast to this plain, the north-eastern end of the 

 county is occupied by a beautiful serrated mountain-range formed 

 of early Tertiary igneous rocks, the highest of which (Slieve Ban, 

 1935 feet) overlooks the lovely lough of Carlingford, a deep inlet of 

 the Irish Sea. The only large river is the Boyne, which forms the 

 southern boundary of the county. Lakes are absent, excepting one 

 or two tiny loughauns. Low-lying, 73J per cent, of the surface 

 being under 250 feet elevation. The area of grass land is below 

 the average (45 per cent.) ; that of crops much above it (40 per 

 cent.). Peat bog is almost absent. The county has been well 

 explored, excepting the inland portions, where not much of novelty 

 need be expected. 



Flora 641 species — a high total, consequent on the great variety 

 of ground which this small county yields. The maritime flora is 

 the most characteristic feature, several of the East Coast group 

 finding here their northern limit. Rarest species : — 



Trigonella ornithopodioides, 5. Scilla verna, 6. 



Seneeio erucifolius, 5. Festuea uniglumis, 5. 



Atriplex farinosa, 6. Cryptogramme crispa, fi. 



32. Monaghan. 



North -central. Area 500 square miles. Inland. Surface 

 undulating, with many low hills, small lakes, marshes, and boggy 

 hollows. All the southern part is formed of drift-covered Silurian 



