Ixviii INTEODUCTION 



per cent, mountain land. The famous flora of Ben Bulben has 

 attracted many botanists, and the whole eastern half of the county 

 is now well explored. Except for Mr. Colgan's work in the Ox 

 Mountains, the barer western half (Leyny and Tireragh baronies) is 

 still a te7Ta incognita. 



Flora 606 species. The dominating interest of the vegetation 

 is the alpine flora of the Ben Bulben group of mountains. Con- 

 sidering the extent and variety of the coast-line, the maritime flora 

 is poor —a feature characteristic of the west coast. Two plants are 

 confined to this division — Arenaria ciliata, which has here its only 

 British habitat, and Saxifraga nivalis. 



Eare and characteristic species : — 



Thalictrum alpinum, 5. Polygonum viviparum, 3. 



Silene acaulis, 4. Pea alpina, 2. 



Arenaria ciliata, 1. Elymus arenarius, 5. 



Saxifraga aizoides, 5. Adiantum Capillus -Veneris, 6. 



Saxifraga nivalis, 1. Aspidium LoncMtis, 6. 



Galium sylvestre, 6. Polypodium Dryopteris, 4. 



29. Leitrim. 



North-western. Area 613 square miles. Almost entirely in- 

 land, having a low rocky coast line of three miles on its NW. 

 margin. A long narrow county, cut almost in two in the middle by 

 Lough Allen, a large lake lying among high Coal-measure hills 

 (Slieve Anieran, 1922 feet). The northern half consists largely 

 of table-topped cliff- walled limestone mountains (Truskmore, 2113 

 feet), being the eastern part of the Ben Bulben range of Sligo. The 

 southern half is low and undulating limestone and calp country, 

 fertile ridges alternating with bogs and numberless small lakes. 

 The infant Shannon flows from the north through Lough Allen, 

 and expanding as it enters level ground, forms an imposing stream 

 along the SW. boundary, with numerous lake-like expansions. 

 Almost equalling Lough Allen in size is Lough Melvin, lying at the 

 northern extremity, and belonging chiefly to this county. Condition 

 of the surface nearly normal, 58 per cent, being returned as grass 

 land, and 20 as crops. The whole of this varied county has been 

 more or less explored, but no part does not require further work. 



