Marcli, 1909 The Irish Nat iD'alht, 57 



A BOTANICAL TOUR IN THE ISLANDS OF THE 

 FERGUS ESTUARY AND ADJACENT MAINLAND. 



BY ]MISS M. C. KNOWLES AND R. D. O'bRIRN. 



The Shannon tide runs fast at flood between Tarbet and 

 Kilkerin Point, thence it finds a clear channel as far as Foynes, 

 about a mile in average width, between bluff banks of the 

 grits and shales of the Coal-measures. At this point the lime- 

 stone is uncovered, and at once the scene changes ; the hills 

 on the Litnerick shore recede towards the south ; alluvial 

 lands reclaimed from the river alternate with low limestone 

 crags. 



We had, as the Irish Naittralist has recorded C), searched 

 these crags in the vain expectation of finding the plants 

 characteristic of Burren, for the Burren limestone extends into 

 the Limerick Barony of Shanid. 



Disappointed there, we noted that the islands in the Fergus 

 are of the same formation, and as their botany seemed never 

 to have been critically examined, we arranged an expedition 

 to explore them for August, 1907, and a detestable wet time it 

 proved. 



The Fergus discharges into the Shannon by a great estuary 

 guarded at the mouth by a double rampart of limestone 

 islands. The more southern group, lying in the opening of 

 the stormy river, which is here some five miles wide, may be 

 fancied the outl3'ing fortifications of the citadel. Its principal 

 islands are Inishcorker, Inishtubbrid or O'Grady's Island, 

 Inishmacowney, also called Horse Island, Canon Island and 

 Inishloe. 



The true bar 01 the Fergus, however, is formed by the 

 northern group — Deer Island, Coney Island, Rat Island, 

 Feenish, Deenish and Inishmacnaghtan. 



BcA'ond these lies a huge tract of the finest slobland. the 

 reclamation of which is an enticing engineer's question. 

 Untold Treasury money has been thrown into the river in 

 attacking a corner of the problem in the wrong way. 



The strike of the strata in these limestone islands is north- 

 east and south-west, so that their cliff-faces, where there are 



(^) /. N., vol. xvi., pp. 185-201. 



