66 Proceedings of Philosophical Societies. [July, 



is called hy the inhabitants Slicaw-my-clough, which signifies 

 ■"the strong mountain." The granite here is large grained. 

 Two varieties of mica slate are met with on Slicaw-my-clough, 

 the first occurring in thin strata where the Foxdale river bends 

 to the north, and being traversed by veins of schorl and quartz 

 <:rystallized in alternate bands ; the other appearing in two or 

 three detached places, and consisting of fine grains of quartz 

 and mica intimately blended with small crystals of schorl. 



The gneiss near the Dun gradually passes into a chlorite slate 



• very regularly stratified, the strata running north-east and south- 

 west, dipping at a considerable angle to the south-east. A bed 

 occurs here about 12 or 14 feet wide, which is between well- 

 defined strata, but is itself in a state of confusion. It is much 

 decomposed on the surface, and is traversed by a vein composed 

 partly of clay and partly of a stalactltic substance united with a 

 considerable portion of lime and a few specks of galena. This bed 

 may be traced from the road side beyond the ridge, and along 

 the course of the stream, about half way between the former 

 spot and the sea till it is lost there. 



The sections of the hill over which the road passes to the 

 north of Douglass Bay, shows the occurrence of veins and beds 

 in the Killas which cannot well be referred to whin or elvan 

 dyke, although they appear to approach the latter on Peel Hill, 

 and between Portle Murray, and the small patch of limestone 

 to the south, and in a quarry at Port Eshee similar appearances 

 are observable. 



At Canal Ferrane there is ati unstratified bed of a crystalline 

 texture, of a dirty flesh colour, full of fossils, and exceedingly 

 hard, which Dr. Berger has omitted to mention. It presents a 

 ■ rugged appearance along the beach, so nearly resembling that 

 of the amygdaloid with which it is connected, that it might be 

 mistaken for a portion of the same bed. 



April 21. — The reading of the " Observations on the Geology 

 ' of the Isle of Man," by J. S. Henslow, Esq. M.G.S. was con- 

 -cluded. 



The sandstone at Peel which is stratified occurs both fine 

 grained, and under the form of a breccia, with spangles of mica 



• dispersed through it, and occasionally mixed with much argilla- 

 ceous matter. Towards the northern extremity of this formatioa 

 near Knock shally, it terminates in an unstratified breccia, con- 

 taining limestone, agate, and ferriferous carbonate of lime. 

 Many of the agates are of a large size, and very beautiful texture, 

 but full of flaws so as to be unfit for the purpose of the lapidary. 

 Veins of crystallized carbonate of lime traverse the bed in every 

 direction, and pass through every substance which they meet 

 with in their course, even the smallest ao;ates. 



A portion of the bed of amygdaloid near Castle Town consists 

 of a trap tufl", or conglomerate, occurring in patches, which over- 

 lie and fill up the cavities in the wacke of which the remaining 



