Stewart — On the Botany of Lough Allen. 427 



stances is there any attempt to ornament the cottages by even the 

 simplest flowers. 



The entire district is inelnded in the Connaught coal-field, one of 

 the few tracts of coal-measures which remain in Ireland. The rocks 

 composing the strata lie far down in the Upper Carboniferous series ; 

 they rise on the east side to an elevation of nearly 2000 feet. These 

 monntains are considered by the officers of the Geological Survey as of 

 the age of the English Yoredale beds, and therefore at the base of the 

 Upper Carboniferous, and in immediate succession to the great moun- 

 tain limestone series, so well developed in the Ben Bulben range to 

 the north-west. The strata are well exposed in the admirable section 

 made by the Stony River, which in rainy weather rushes down the 

 west side of Slieveanierin as a mountain torrent. Massive beds of what 

 seems a valuable hematite are interstratified with soft black shales, and 

 occasional bands of sandstone. These beds are dominated by sandstones 

 that appear in low cliffs as tabular masses, and are referred by Profes- 

 sor Hull to the millstone grit. The elevated plateau thus constituted 

 was at one time continuous over a wide area, extending, as we still 

 see, across Cavan to Fermanagh on the east. The action of denuding 

 agencies, persistently operating for long periods, has resulted in sculp- 

 turing the surface into its present outline, and thus we have now the 

 Slieveanierin, and Cuilceagh ranges, and their subordinate hills, sepa- 

 rated by broad valleys and deep glens excavated in the underlying shale. 

 At the south end of Lough Allen there is a small exposure of mountain, 

 limestone rocks, on which flourish several plants not met with else- 

 where in the district. The rocks forming the low hills on the west of 

 the lough are classed as equivalents of the lowest coal-measures of 

 England, and contain thin seams of indifferent coal. In several 

 places this coal is extracted in small workings of a most primitive 

 character. 



On the Arigna river, three and a-half miles north-west of Drum- 

 shambo, are extensive iron-works, but out of use for half a century, 

 and now in a state of dilapidation, heaped up with rubbish, and over- 

 grown with weeds. Stores of valuable metal are all around, and, if 

 coal suitable for smelting could be obtained, there is no reason why 

 these old buildings should not be replaced by still more extensive 

 works. A district, with rocks such as those just clescribed, nowhere pre- 

 sents a variety of vegetation, or yields plants of much rarity. But, as 

 our uplands have an altitude almost equal to that of the Ben Bulben 

 range, only some twenty-five miles to the north, it might nevertheless 

 reasonably be hoped that some of the rarities of that famous botanical 

 region would extend to these neighbouring hills. Such is not the case, 

 and the result of the present exploration is still further evidence as 

 to how profoundly the flora of a country is controlled by petrological 

 conditions. It is further to be remarked that this region, now so bare, 

 was at one time well wooded, and that the flora has responded to the 

 changed conditions, so that sylvan plants are at present extremely 

 scarce. The list Avhich follows irududos only plants which Avere 



14. 1. A. PilOC, SEK. II VOL. IV. — SCIE.NUE. '2 II 



