Alfred Bell — Post-glacial Drifts of Ireland. 449 



Slieve Bloom range, into King's and Queen's Counties. But west of 

 the Ox and Curlew mountains in Sligo, the shores and low grounds 

 are covered with sandstones and granites transported in the opposite 

 direction. 



The largest erratic in Ireland lies in the valley of the river Tay, 

 near Kilmacthomas, Co. Waterford, measuring 50 X 35 X 18 feet, 

 carried 2|- miles away from the parent rock. 



It is singular that no fossils have been noticed in the gravels of so 

 great a part of Ireland. A few Mytili in Sligo, a Buccinum in 

 Moate, Co. Westmeath, and a few fragments in Tipperary, appear to 

 be all that have been seen. 



Having thus outlined the non-fossiliferous (?) Pleistocene deposits, 

 I turn to the drifts which have yielded organic remains. 



Beneath 25 feet of Boulder-clay, in a river-valley, near Gort, Co. 

 Galway, sands and clays occur, according to Mr. Kinahan, containing 

 sticks, fir-cones, etc., and in Queen's County, beneath a similar ac- 

 cumulation, stratified clay, sand, and gravel have been proved in 

 boring for coal. In two or three places beds of peat were jDresent. 

 These infra-clay beds may be either pre- or inter-glacial. 



From Donegal a drift of a totally difi'erent kind to that first 

 mentioned proceeds eastward, covering the northern counties of 

 Deny and Tyrone, picking up fragments and rock-masses, till, in the 

 Belfast and more southern districts, it forms a tenacious clay, full of 

 blocks, sometimes glaciated, of quartz, syenite, mica-slate, porphyry, 

 granite, and Antrim Chalk, varying from a pebble to large masses of 

 several tons in weight, as well as those of local origin. At Boveragh 

 in Derry the clay rises to a height of 450 feet above the sea, and 

 contains many fossils although of but few species. These are Turri- 

 tella terebra, Cyprina, and Leda oblonga. 



In Fermanagh, Tyrone, and Armagh, local boulders predominate, 

 the northern rocks being scarce. In the river- valleys and those sur- 

 rounded by hills and high ground, the sands aud gravels are often 

 laminated and interstratified. As no fossils are known from them, 

 they may be the remnants of interglacial deposits. 



On the banks of the Lagan and the southern shores of Belfast 

 Lough the clay has yielded to Messrs. Bryce and Hyndman a good 

 series of fossils, thirty-seven species in all. Of these, only two — 

 Zeda oblonga and Trophon clatliratum — are extra-British. Buccinum 

 fusiforme is, I think, a doubtful identification. Two specimens of an 

 almost extinct British form, Fusus contrarius, were also collected. 

 The other species are added to the list of fossils from the Dublin 

 district, with which they closely agree. 



From a stratified bed of gravel on the side of the road from Lome 

 to Glenarm, Mr. Jeffreys procured a series of fossils totally differing 

 in character from those just mentioned. Out of sixteen species of 

 shells, not less than seven are extra-British foi'ms. These are Leda 

 oblonga, TelJina proxima, Bhynclionella psittacea, Natica. (ifjiuis, P/earo- 

 toma Pingelli (Vahlii), Troplion clatliratum, and TurriteUa erosa. Such 

 an assemblage of outer British forms totally separates this Larne 

 gravel from the drifts of Belfast and Dublin, shortly to be referred to. 



VOL. X. — NO. cxii. 29 



