Clare Island Surrey — Land and Fresh-water Moltusca. 23 5 



Bay and Castlebar district. Louis burgh includes a similar strip south of Clew 

 Bay and between the mountains of Croaghpatrick and Mweelrea and the sea. 

 The Clew Bay and Castlebar district consists of that portion of the limestone 

 area of West Mayo, or areas influenced by limestone Boulder-clays, from 

 Mulranny and Old Head harbour round Clew Bay, and it extends as far 

 inland as the limits of the vice-county. 



BALL/ 7V 'A 



INISHTURKC? n 

 INISHBOHN ^gggk., 



\LOUGH 



MASK 



Fig 1 ' 



.4. COMPARISON OF THE SUB-DISTRICTS. 



A comparison of the different sub-districts into which I have divided the 

 area surveyed is not difficult to make. The islands, except for a stretch of 

 Carboniferous sandstone on Clare Island, are composed mainly of Silurian 

 and metamorphic rocks, so also are the districts of The Mullet, Erris, and Louis- 

 burgh. All are for the most part covered with peat, with narrow stretches of 



