PREHISTORIC BOMBAY*- 1 I" 



sufficiently long to the action of the weather to \»- worn into promi 

 nences and depressions before the deposil of those lying on them. 



Bui the rocks of Bombay do not belong to«this pari of the series 

 For we find here no less than six bauds of fresh water beds inter- 

 stratified with the volcanic rock. Nor do they belong to the older 

 parts in which the other fresh water beds occur. For with the 

 exception of one out of several species of Cypris, a small crustacean 

 allied to the " water flea," no animal organism among the fossils of 

 the two sets of interstratified fresh water beds has been identified a - 

 common to both. 



On the other hand, the fossils of the Bombay fresh water bed 

 belong, apparently, to a later period in the history of the evolution 

 of life on the earth than the others. We find among them the wing- 

 cases of beetles, the bones of a fresh water tortoise, and the skeletons 

 of a small frog {Oxyglossus pusillus), which the absence of certain 

 teeth shows to be closely allied to two existing species, Oxyglossus 

 lima, found in Siam, China and Bengal, and Oxyglossus loevis, found 

 in the Philippines. 



Here, then, is another very important record in regard to the 

 age of our island, showing that its rocks were formed towards the 

 end of the series of the Deccan traps, and when those volcanic out- 

 bursts were beginning to abate in frequency and violence. 



But the Bombay fresh water beds you find on both sides of the 

 island, and they run out into the sea at several places. Moreover, 

 they are continued in Salsette, and, if looked for, would probably be 

 found on the main-land. Wherever they occur they partake in 

 the westward dip we have noticed in the volcanic rocks, the top 

 or latest flows, of which they underlie. 



All this tends to show that the fresh water beds were deposited 

 before Bombay was so broken off from the main-land as we have seen, 

 and that they originally extended beyond the present limits of our 

 island. How far beyond, we cannot say, as we have no means now 

 of knowing how much land has been lost by subsidence, by en- 

 croachments of the sea, and by the action of the weather. 



Now the fossils which we find in the Bombay fresh water beds 

 are such as show that the area which they indicate must have 

 been covered by a shallow muddy swamp of stagnant fresh water, 



