1866.] HAEKNESS — GALWAY. 509 



east direction. In this valley is Lough Inagh, the only lake of a 

 considerable size in the Connemara country^ which has a north-west 

 and south-east position. 



The quartz-rocks are well exposed on the east side of Derryclare 

 Mountain and Bencorr. 



They exhibit on this side of the range an anticlinal axis, on the 

 south side of which is the band of limestone before referred to ; and 

 on the north side another band of limestone is seen in the valley of 

 Gleninagh. This limestone of Gleninagh also occurs at Peliskin, 

 near the north-east side of Lough Inagh, on the road which is 

 now being made from the Clifden Road northwards to Kylemore. 

 As seen at Peliskin it is of a light-grey colour, and has the sub- 

 crystalline nature which the southern band exhibits where it is 

 not charged with serpentine. It dips from the anticlinal which lies 

 to the south of the limestone, and passes conformably under a small 

 area of gneissose rocks which occurs to the north of Feliskin. 

 The rocks, a short distance northwards, soon assume southerly 

 dips, the limestone here occupying a synclinal trough, which, if 

 followed over the mountains westward, would probably be found 

 to connect itself with the synclinal valley of the OwengHn Eiver. 

 Some distance north of Feliskin another antichnal axis occurs, on 

 the north side of which northern dips again prevail ; and above the 

 quartz-rocks limestone again appears, succeeded conformably by 

 gneissose rocks, the latter being in their turn covered unconform" 

 ably by fossiliferous Silurian sandstones, which extend from near 

 Kylemore to the south side of Killery Harbour. 



The valley in which Lough Inagh is situated so distinctly sepa- 

 rates the Maame Tork range of mountains from that of the Twelve 

 Bens of Connemara, as to justify the inference that it originated in 

 a fault. The Maame Tork range, on the east side of Lough Inagh, 

 presents very bold escarpments towards the south-west ; and these 

 escarpments run very regularly north-west and south-east, the 

 direction which the assumed fault takes. 



The arrangement of the metamorphic rocks of the west of the county 

 of Galway has an intimate relation to that which occurs among the 

 rocks of the same nature in the county of Donegal*. It also corre- 

 sponds with that of the Highlands of Scotland, representing the upper 

 'quartz-rocks, the upper limestones, and the upper or flaggy gneiss 

 of the latter country, as these have been described by Sir Eoderick 

 I. Murchison. With reference to the occurrence of serpentine in 

 connexion with the limestones of the metamorphic series of Con- 

 nemara, this has of late become a matter of some interest, in conse- 

 quence of the statement that these deposits afford the Eozoon Cana- 

 dense. The serpentinous limestones of Connemara are of local 

 occurrence ; they usually appear in such districts as exhibit the 

 strata highly contorted and broken up. 



The lines of lamination in the limestone strata have been opened, 



and the laminse have been fractured across, in consequence of the 



contortions to which the strata have been subjected ; and into these 



openings and fractures the serpentine has been subsequently intro- 



* Quart, Journ. Greol. Soc. vol. xvii. p. 268. 



