ANNIVERSARY ADDRESS OF THE PRESIDENT. CXXl 



stone. He says, " Besides the new red sandstone and the old red 

 sandstone, we have in Ireland another red sandstone, or grit, which, 

 I have reason to believe, has frequently been confounded with, or mis- 

 taken for, the carboniferous old red which I have been describing. 

 It is of true Silurian age, as I shall presently show." To distinguish 

 these rocks, so closely resembling each other, Mr. Kelly adopts the 

 provincial term " brownstone," as used by the peasants of the country. 

 The Old Ked Sandstone itself Mr. Kelly divides into three sections; 

 namely, — 1st, a thin band of red conglomerate, composed of pebbles 

 of white and brown quartz, purple hornstone, jasper, and fragments of 

 other rocks ; 2nd, alternating red sandstones and shales, between 200 

 and 300 feet thick ; 3rd, yellowish sandstones with occasional interca- 

 lated beds of limestone or calcareous slate, containing the usual fossils 

 of the mountain-limestone. This series is well seen at the Hook, 

 county of Wexford, and there terminates in the true mountain lime- 

 stone. The same view of the position of this series is taken by the 

 Rev. Professor Haughton, who thus enumerates it from below up- 

 wards : — 1st, Old Red Sandstone and conglomerate, resting uncon- 

 formably on the nearly vertical beds of Silurian slates, alternating with 

 each other, and about 1500 feet thick, without fossils; 2nd, alter- 

 nating beds of red conglomerate, red micaceous sandstone, and red 

 shales, 382 feet in thickness, containing remains of plants referred 

 to Knorria dichotoma^ thus representing the yellow sandstone ; 3rd, 

 older limestone, composed of a series of alternating beds of arenaceous 

 limestone, black shale and sandstone, and red ochreous and flaggy 

 limestones, the total thickness being 85 1 feet : many of the fossils 

 are stated to be new, but others are well-known carboniferous fossils ; 

 4th, dolomite-bed without fossils, 385 feet thick ; 5th, newer lime- 

 stone-beds alternating with calcareous shales, and containing the 

 usual carboniferous fossils. Now, Professor Haughton considers the 

 plant-beds of this section as equivalents of the yellow sandstone of 

 Dr. Griffith, and as distinct members of the Carboniferous system, 

 though constituting the Upper Devonian of the Goverament geo- 

 logical surveyors ; and he further observes that it is impossible to 

 draw any line of separation between these beds and the lower sand- 

 stones and conglomerates, so that *' the group of rocks described is a 

 continuous whole, and as such should be classed with the Carbo- 

 niferous system, not a single characteristic Devonian fossil having 

 been found in this or any other part of Ireland." Professor Haughton 

 then observes, that " too much importance has been attached to sy- 

 stems and system-makers hitherto in geology ; and many of the con- 

 troversies waged respecting silurian and Devonian groups, have had 

 their origin in, or, at least, owe their continuance to a desire on the 

 part of the controversialists to extend, beyond their due boundaries, 

 merely local subdivisions and names ;" but this caution, however ap- 

 plicable it may have been to that stage in geological science, when ob- 

 servers, striving to unravel the tangled web of the earth's mineral his- 

 tory, were naturally led to attach undue importance to each fragment 

 which they had succeeded in reducing to order, is no longer neces- 

 sary, as our modern geologists are fully aware that they must seek in 



