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Kot a fossil or water mark could I see, in tho different strata 

 below tlie surface; but above it were fragments of a white 

 rock, similar to variegated marble in wbich lay fossil shells, 

 mostly microscopic. These were evidently compact masses • 

 of limestone, probably having undergone a partial metamor- 

 phic process. The fossil shells are indefinite in outline and 

 appear mere patclies of white crystalline carbonate of lime, 

 wMcli a few centuries longer of exposure would doubtless 

 leave merely as white veinings or blotcbes. 



The general geological features of Bound Island stand as a 

 key to open out to us the immensity of the periods in which 

 the volcanic action was going on here and at the Mauritius '■> 

 and a convincing proof that since these isolated rocks were 

 upheaved an immeasurable interval of time must have elapsed. 

 Near and round the top and centre of the island, are 

 groups of volcanic rocks, many tons in weight ; but there is 

 no appearance of any flow of lava, 



The&e rocks may have been thrown up from the crater, 

 which was probably never very active. There is not the least 

 sign of any depression or indication of a crater in the summit. 

 The action of the elements which has been at work for such 

 an incalculable time, disintegrating these rocks has doubtless 

 filled up the opening, and formed it into a solid mass. 



Long after the upheaval of Eound Island volcanic action 

 was still vigorous at Mauritius and its vicinity. Submarine 

 volcanoes were active, which rose above the sea, and were 

 again depressed. 



The Diamond rock and others, appearing so near the sur- 

 face that the waves break over them in the calmest weather, 

 are the top of very high submerged mountains, which were 

 once in all probability united to the main land. 



At the table rock where we landed is a flow of lava from 

 the S. W., which is filled with detached pieces of scoria, si- 

 milar to that at Mauritius, but difiering from that in the stra- 

 ta of the island. 



The current of lava flowed back againts the bold and inac- 

 cessible sides of Round Island, cooling in waves and remaining 

 a silent witness to the wonderful agency at work at that time. 



