15S The Irish Naturalist. [June, 



Here, below some feet of sandy and muddy beds, the recent 

 creation of the River lyagan, we find a bed 12 feet thick of blue 

 clay, which examination shows to be clearly divisible into two 

 zones — an upper clay, exceedingly fine and pure, full of a rich 

 and luxuriant fauna characterized by species which live in from 

 5 to 10 fathoms of water ; and a lower zone, more sandy, which 

 yields in abundance remains of the Grass-wrack, Zostera 

 marina^ and shells, such as Scrobicularia piperata, Tapes 

 decussatuSy and Telliyia balthica, that are usually found living 

 with the Grass-wrack on mudd}^ shores between tide-marks. 

 Under these clays we see, intercalated between thin beds of 

 grey sand, a layer of peat, which contains remains of Scotch 

 Fir, Hazel, Alder, &c., as well as bones of the Red Deer, Wild 

 Boar, and Irish Elk/ The next bed in order of descent is a 

 fine red sand, a deposit that in many places in the neighbour- 

 hood of Belfast attains an extensive development, and which, 

 though its stratigraphical relations have not yet been worked 

 out, there is good reason for supposing to correspond with the 

 sands and gravels which form so important a feature in the 

 glacial series about Dublin. And lastly, this bed of sand 

 reposes on Boulder-clay. 



Comparing now this section with the beds on the foreshore 

 at Bray, we will be immediately struck with the exact parallel- 

 ism. The deep-water clay which forms the uppermost bed of 

 the series at Belfast is indeed unrepresented at Bray, but the 

 others correspond zone for zone, and the clay and peat are 

 even characterized by the same fossils. And we may with 

 advantage carry our comparison a little further. The peat- 

 bed is to be found in many spots in the north-east ; and in 

 other places at Belfast, and at Downpatrick, it is to be found 

 underlying thirty feet or more of the blue clay. Again, at 

 Ivarne, the Scrobicularia clay (as we may call the lower zone), 

 which is also very persistent along the north-eastern shores, 

 has, superimposed on it, 19 feet of stratified marine gravels, 

 which contain flint implements of Neolithic age from top to 

 base, though none are found in the clay. At Kilroot, mid- 

 way between Belfast and I^arne,the beds present an appearance 

 exactly like that seen at Bray, for here, near low water-mark, 



* Praeger, op. cit.^ and Froc. B.N.FX> for 1891-92, p. 416. 



