Geology and Geogrnpliy. 877 



under consideration, with the exception of a few local variations, 

 which can be easily explained, also attests the action of currents 

 from the west and north-west. Mr Bryce next spoke of the 

 magnesian limestone of Cultra, near Hollywood, in the county 

 of Down, which he remarked occurs within a space about a mile 

 Jong and a few inches broad. It is fine grained and compact, 

 and is generally of a grey or bluish-grey colour. It alternates 

 in thin layers with strata of sandstone, which there cau be no 

 doubt is the lower portion of the new red sandstone series. A 

 bluish-black shale, of a soft and friable texture, and unctuous 

 feel, but destitute of bituminous matter, is associated with the 

 sandstone in some places, and seems to be inferior to the lime- 

 stone ; it effervesces feebly with acids. The beds of sandstone 

 below the limestone are often conglomerated in their structure, 

 and are interstratified with a conglomerate containing frag- 

 ments of quartz, grey wacke, with a yellow earthy and a grey crys- 

 talline limestone imbedded in a slightly calcareous base. To 

 these greywacke slate succeeds. The conglomerate and sand- 

 stone below the limestone agree very closely in character with 

 the calcareous conglomerate of the west of England, and the 

 " inferior red sandstone 11 of Professor Sedgwick, which underlies 

 the magnesian limestone of the east of the same country, and 

 which that distinguished geologist has identified with the 64 Rothe 

 Todliegende' 1 of Germany. The calcareous blue shale alluded 

 to seems beyond doubt the equivalent of the tc marl slate 11 or 

 " kupfersehiefer, 1 * the compact bluish-grey limestone to hold 

 the place of the " Zechstein,' 1 while the upper red sandstones 

 or gypseous marls of the vicinity of Belfast are the types of the 

 " keuper and hunter sandstein, 11 the muschelkalk being absent 

 in Ireland as in England, and the rauch wacke being represented 

 only by a partial and unimportant yellow limestone. Mr Bryce 

 remarked it was a remarkable instance of the uniformity of for- 

 mations, that there should occur in an insignificant spot, rather 

 less than a mile long and only a few inches broad, a series of 

 beds, which seem the exact equivalents, in relative position and 

 mineral structure, of deposits which occupy in the east of Eng- 

 land a space 200 miles long and f rom ten to forty broad, and on 

 the continent of Europe are still more extensive. Mr Bryce 

 then alluded to several ether points connected with the geology 



