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and carried away the tops of many of the anticlinal convolutions 

 formed in them, and left the beds thrown up on their edges, as we 

 now find them, the conglomerate, or lower band of the Old Eed Sand- 

 stone was the first — the foundation layer of the succeeding geological 

 age. This layer was laid down upon the edges of the older rocks as 

 they happened to present themselves, whether slate, grit, quartz, lime- 

 stone, or any other rock. In Ireland it rests on thirteen varieties of 

 older rocks ; it lies on mica slate at nineteen places where the junctions 

 are exposed ; on gray slate in twenty-seven, and so on. This conglo- 

 merate of the Old Red Sandstone is a most important index in geology. 

 It is the boundary between two distinct periods of organic life. 



Carboniferous, or Mountain Limestone. 



Of the Mountain limestone there is also not much : there are two 

 beds of limestone about five feet thick, on the shore of Tornaroan one 

 and a half mile east of Ballycastle, visible at one place a little above 

 high-water. The strata have all an eastward dip at this place, and as 

 the limestone on the west side rises into the face of the cliff, and on 

 the east dips under sea level, there is but a small part easily accessible 

 for examination. This limestone has coal measures over it, and coal- 

 measures under it, and so far, it has a likeness to the colliery at Burdie 

 House near Edinburgh, in which the limestone has coal above it, and 

 coal below it in a similar way. 



This Antrim coal district appears to be a prolongation of the coal 

 field of the Eorth and Clyde valley, in Scotland, They are in the 

 same strike and position with regard to the older adjacent rocks ; and 

 as no one can doubt that the whole of the carboniferous formation of 

 the British Islands was deposited at the same period, it is likely that 

 at Antrim and Glasgow, two places not very far distant, there would 

 be a typical likeness in the rocks which compose them both, as to litho- 

 logical character and succession. The valley of the Eorth and Clyde, 

 which is in the carboniferous rocks, may be prolonged on the map of 

 Great Britain and Ireland. It passes through Ballycastle, across Lough 

 Neagh, by Dungannon, Caledon, and Clogher to the Connaught coal 

 district about Lough Allen. This shows that the limestone at Bally- 

 castle, as well as the coal rocks there, forms a part of the great band 

 stretching between the Erith of Forth and the Connaught coal district. 

 Besides this, a small bag of fossils, got at Ballycastle in the limestone, 

 and examined by Mr. M'Coy at Dublin, were all carboniferous, as the 

 following list shows : — 



Cycloceras annularis (Flem.), . . Producta fimbriata. 



Bellerophon reticulatus (M'Coy), . Athyris decussata. 



Euphemus Urii (Phil.), .... Astrea pentagona. 



Pecten flabillulum ( M ( Coy), . . Fenestella carinata. 

 Producta Edelburgensis (Phil.), 



