356 NOTES ON THK GEOLOGY 



through the liberal assistance of Professor Bailey, and his great 

 skill in the use of the microscope, I am enabled to assign to a part 

 of them, at least, a place among the rocks, with confidence. The 

 following paragraph, from Mr. Weaver's Observations on the 

 Discoveries of Ehrenberg, contained in the Annals of Natural 

 History for June, 1841, did, indeed, furnish the clue to the results 

 at which we have arrived. 



" The compact limestone rocks which boimd the Nile in the Avhole 

 of Upper Egypt, and extend far into the Sahara or Desert, as well 

 as the west Asiatic compact limestones in the north of Arabia, are in 

 the mass composed of the coral animalcules ( Polythalamia of Ehren- 

 berg, the same as the Foraminifera of D' Orbigny ) of the European 

 chalk. This affords a new insight into the history of the formations 

 of Lybia, from Syene to the Atlas, and of Arabia, from Sinai to 

 Lebanon." 



The perusal of this paragraph led Prof. Bailey to request me 

 to send him specimens. This was done, and very soon he was 

 so obliging as to return the following interesting results : 



" I hastened," says he, "to examine microscopically the powders 

 which you kindly sent, and obtained the following results : 



"No. 136. From the Pyramid of Cheops, near Cairo: Polythal- 

 amia distinctly present, but rare. 



"No. 2. Chalky limestone, west side of Anti-Libanus: Polythal- 

 amia abundant. 



" No. 13. Limestone one mile west of Damascus : Polythalamia 

 abundant. 



" No. 5. Chalky limestone. Mount of Olives : Polythalamia 

 abundant. 



" No. 6. Do. Beyroot. Polyathalmia present, but not so abundant 

 as in No. 5. 



No. 30. Argillaceous limestone, river Barida, Anti-Libanus : 

 Polythalamia abundant. 



" This examination then confirms Ehrenberg's statement with re- 

 gard to the presence of coral animalcules ( Foraminifera of other 

 writers) in the limestones of Arabia. His statement refers to the 

 compact limestones, which he says are thus composed, ' from Sinai 

 to Lebanon.' I do not see, in Weaver's abstract of Ehrenberg's views, 

 any notice of the occurrence of these shells at Jeaisalem, or Damas- 



