July, 1903. 173 



FORAMINIFERAI., HIGH-LEVEL BOULDER CLAY, 



IN THE COUNTY OF DUBLIN, 



AND IN DUMFRIESHIRE AND AYRSHIRE; 



With Observations on the Origin of BouIvDEr Ci.ays. 



by joseph wright, f.g.s. 



In 1873 Rev. Maxwell Close, e.g.s., read a paper before the 

 Royal Geological Society of Ireland, on " The Elevated Shell- 

 bearing Gravels near Dublin."^ In this paper the author 

 records the occurrence of molluscan shells in the sand and 

 gravel beds at Ballyedmonduff, at an elevation of 1,000 feet 

 above the sea, and at Caldwell Castle^ at an elevation of 1,200 

 feet. Five years later I visited the former locality, and 

 brought away a small quantity of the finest of the material 

 for microscopical examination ; the shell fragments through 

 it were much worn by exposure to the weather.^ The fol- 

 lowing Foraminifera were obtained : — 



IVIilloIina Boueana (d'Orb.)?— Rare. 

 PolystoiYicIIa crispa (Linnd). — Rare. 

 P. striato-punctata (F. & M.). — Rare. 

 Nonlonlna depressula (W. &J.). — Common. 



A few months ago I received from Mr. H. J. Seymour, of 

 the Geological Survey of Ireland, two packets of Boulder 

 clay, which he kindly got for me from Mr. J. de Witt Hiuch, 

 of the National Library, Dublin. They were from Rockbrook 

 and Larch Hill, County Dublin.^ The following is a list of 



the Foraminifera : — 



Rockbrook. 

 Boulder clay, Rockbrook, 500 feet above the sea. Weight of clay, 

 24"8 oz. Tro3^ After washiug, 7*2 oz. fiue, 4 oz. coarse,-* stones angular and 

 rounded, some of them very much rounded as if they had been so 

 formed on an exposed sea beach. Foraminifera most abundant. 

 IVIIIioIina seminulum (Linne). — Very rare. 

 Verneuilina pygmaea (Egger). — Very rare. 



■■ Journ. Roy. Geol. Soc. Ireland^ vol. iv., new series, pp. 36-40, 

 1873-77. 



' Proc. Belfast Nat. Field Chib, 1879-80, app., p. 156. 



^ For information regarding these clays, see " A Contribution to 

 Glacial Geology of County Dublin," by J. de Witt Hinch, Irish Naturalist, 

 October, 1902. 



^ The sieves used for washing the clays were a galvanized wire sieve, 

 16 meshes to the linear inch, and a miller's silk sieve, 150 meshes to the 

 linear inch. 



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