GEOLOGICAL SOCIETY OF DUBLIN. 103 



argillaceous limestone or calp, which form the precipitous cliffs of 

 Dartry mountain facing the west, and which near the summit are 

 capped by the upper or splintery limestone." 



8. Again, at page 10. — " Excepting in the northern counties, where 

 the succession of the limestone series is fully and clearly developed, it 

 is almost impossible to determine with any precision on the point where 

 the lower limestone may be said to terminate, and the calp or the upper 

 limestone to commence. In many localities of the midland and southern 

 counties, the black sliale or calp series is altogether wanting, or it occurs 

 so sparingly that without a laborious and minute examination it will 

 not be detected." 



9. Page 11. — "It would be tedious, and almost endless, to enter 

 into a particular description of the numerous localities in which the 

 calp series occurs in the north of Ireland : at present we need only ob- 

 serve, that the shale district, extending from Emyvale in the county of 

 Monaghan, to Brookborough in the county of Fermanagh, known by 

 the name of the Slieve-Beagh Mountains, has long been considered to 

 be the true Coal formation, and sanguine expectations have been enter- 

 tained of the discovery of workable beds of coal ; but having ascertained 

 that in the order of succession it forms a portion of the calp series, it 

 appears very improbable that these expectations will be realized." 



10. Page 11. — "Upper or Splintery Limestone. This rock is of 

 comparatively rare occurrence in Ireland, and its superficial extent is 

 insignificant. Owing to its containing the greater number of the fossil 

 organic remains which occur in the lower limestone, it is difficult in 

 some localities to distinguish between them, particularly where the calp 

 series is wanting, which frequently happens." 



11. Page 12. — " In the valley of the Barrow at Carlow, where the 

 whole Carboniferous Limestone series of the south is clearly developed, 

 it would appear that the calp or black shale division is wanting ; and 

 that the upper limestone rests directly on the black marble beds of the 

 lower." 



12. Page 12. — " In Belmore mountain, the thickness of the upper 

 limestone amounts to 650 feet. In Benbulben, it is 500 feet ; and at 

 the eastern base of Culkagh mountain, in the county of Cavan, it is 

 600 feet." 



13. Page 13. — "Millstone Grit. Eocks decidedly belonging to 

 this series are only to be met with in the mountain district surrounding 

 Lough Allen, in the counties of Roscommon, Leitrim, Cavan, and Fer- 

 managh, hitherto known by the name of the Connaught coal district ; 

 and in the shale district extending from Drumquin, in the county of 

 Tyrone, to the neighbourhood of Pettigo, in the county of Fermanagh." 



I have now come to an end of those paragraphs of the " Outline" to 

 which I mean to have reference ; they are thirteen in number. 



As the subdivision of the Carboniferous formation stands arranged 

 in this " Outline of the Geology of Ireland," I object to it, and am pre- 

 pared to maintain that a great part of it is visionary. The subdivision 

 of the limestone, as given at the quotation No. 2, and the descriptions 



