{Proceedings Belfast Naturalists' Field Cluh.— Appendix 1885-1886.) 



A LIST OF THE CRETACEOUS FORAMINIFERA OF 

 KEADY HILL, COUNTY DERRY. 



BY JOSEPH WRIGHT, F.G.S. 



$ 



N the year 1874 I published a List of the Cretaceous Microzoa of Ireland. 

 vjK It was the result of three years' exploration in the chalk of the Counties 

 \^y of Antrim, Derry, and Down, the only counties in Ireland where rocks of 

 this age occur. The "Greensand in Ireland appears to be almost devoid of 

 Microzoa. Only two Foraminifers have as yet been found in it — viz., Orbito- 

 lina concava,* and Cristellaria rotulata.f I have on one or two occasions 

 examined greensand rocks under the microscope, but failed to find any trace of 

 these organisms in them. With the above two exceptions, all the Microzoa 

 found in the Irish Cretaceous rocks have been obtained from a mealy powder, 

 known as chalk powder, which is of frequent occurrence in cavities in the 

 flints. I do not remember to have ever visited a chalk exposure with flints 

 that did not yield, on searching, at least some of this powder. At some places 

 it was very scarce, at others it was abundant. It may have been merely acci- 

 dental, but flints found in the vicinity of the sea usually contain a much greater 

 quantity of the powder than those found farther inland. 



The chalk in Ireland is a hard, compact limestone, known as white " lime- 

 stone," of the same age as the soft white chalk of the South of England, but 

 very different in character, the hardness of the Irish stone being presumably 

 due to the heat and pressure of the overlying basalt. The flints found in it are 



* Tate, Cretaceous Rocks of Ireland, Quart. Journ., Geol. Soc., 1865. 

 + Wright, Cretaceous Microzoa of Ireland, Eep. andProc, Belfast Nat. Field Club, 1874, 

 app. p. 73. 



