1842.] Capt. NewboloVs Geological Specimens. 1135 



numerous specimens he examined, any traces of the spongeous remains 

 found in the agates of Europe and jaspers of India. The Egyptian 

 agate consists of small, irregular light coloured grains, imbedded in a 

 banded siliceous matrix. 



The granites of Sinai and Syene, have their types in those of Southern 

 India : they are composed in general of felspar, quartz, hornblende 

 and a little mica, the felspar usually pale rose-colouTed. They pass 

 from close grained to porphyritic. The rock said to be that struck by 

 Moses, lying in the valley of the Forty Martyrs at the base of Horeb, 

 is a mass of the ordinary granite, penetrated by a vein of smaller grained 

 granite, in which I found the narrow apertures through which the 

 monks of St. Catherine state the water to have gushed. The rock 

 is evidently not in situ, but a dislodged mass from the granitic heights 

 that overlook the valley. 



I regret having left behind me in England, specimens of the celebrat- 

 ed breccia di verde, trap, hypogene schists, serpentine, slate, and sand- 

 stones that prevail in the Thebaid, between Cosseir on the Red Sea and 

 the Nile : besides these and the formations already mentioned is a 

 rock, more recent than all, and still in progress of formation, (No. 12,) 

 found but as a littoral deposit, not only on the shores of the Red Sea, 

 but on those of the Mediterranean, to a great extent, though super- 

 ficial. On some parts of the eastern coast of Egypt, it has been 

 elevated above 100 feet above the level of the sea, and imbeds many 

 species of recent pelagic shells, corals, and, near the sea, bones of 

 camels, grains of sand, pebbles, &c. cemented together, by carbonate 

 of lime, into a rock varying from a friable mass loosely agglutinated, 

 to a compact travertine. (No. 12 ?) It occurs from an inch to several 

 feet in thickness. On the shores of Aden, fragments of lava are included ; 

 and on those of the Bosphorus ; and at Smyrna, Mityline, and Rhodes, I 

 found fragments of limestone and other rocks in the vicinity : at the 

 last place also, pieces of ancient pottery elevated a few feet above the 

 level of the sea. 



In addition to the foregoing specimens there is also a series of more from 



Southern India, all of interest, and some highly instructive ; but as the catalogue con- 

 tains but few observations, it will be printed amongst those of the Museum. — Ed. 



