BY JOHN SHIRLEY, D.SC, F.M.S. 7 



the Syrian and northern Egyptian coasts. The Revd. 

 A. H. Cooke, says* that " of 818 shells collected by 

 Macandrew at Suez, 17 are undoubtedly Mediterranean." 



It would be well to try and ascertain in what geologic 

 age the great equatorial current swept in an unchecked 

 stream across the Pacific, Indian and Atlantic Oceans, 

 •carrying with it the vivifying Avarmth acquired in its long 

 course through tropical seas. In the Cretaceous age the 

 southern type of the system attained a great development 

 on both sides of the Mediterranean basin, and covered a 

 vast area of the north of Africa. In the Sahara region, 

 forming the interior of Algeria, it extends in broad plateaus, 

 ending in abrupt escarpments, showing the varied outlines 

 that might have been an old shore line. In these rocks 

 the various Cretaceous subdivisions from the ^f^eocomian 

 upwards have been recognised. One important member 

 of the sj^stem forms the upper part of the " Nubian Sand- 

 stone," which is so important a factor in determining the 

 character of the landscape in north-eastern Africa. This 

 formation extends eastwards into Syria, and is found in 

 the region of the Lebanon. In the Eocene epoch the most 

 widely distributed marine deposit is represented by the 

 nummulitic limestone, which extends from the Alps to the 

 Caucasus, through northern Africa, from Persia to the 

 Suleiman Mountains, and is found again in China and 

 Japan. Lyellf says of it — " The nummulitic limestone 

 is of world-wide extent, and contains many corals of large 

 size, of genera now common in tropical seas, some of the 

 same fossil species ranging from Scinde in India to the 

 West Indies." A. GeikieJ believed '' that the open Cre- 

 taceous sea must have stretched through the heart of the 

 Old World." 



The Cretaceous fauna, as seen in European forma- 

 tions, includes such genera as Strombus, Fusus, Fasciolaria, 

 Oliva, Pleurotoma and Conns, and, in India, Cyprcea and 

 Voluta, which in the present age are most abundant 

 in warm seas. In Eocene times the affinities of the 



♦Cambridge Natural History, jNIolluscs and Brachiopods, p. 369. 

 fPrinciples of Geology, Vol. I., p. 207. 

 + Geology, p. 325. 



