158 NATURAL HISTORY. 



islands of which Salsette is the largest and Bombay the centre, cover 

 a great number of sounds and inlets, mostly centring in Bombay 

 Harbour. Many of these are fast disappearing before natural silt and 

 artificial embankments, expecially the group west of Salsette and 

 that east of Hog Island and Karanja, both of which have been changed 

 from islands to peninsulas within living memory. This has given 

 rise to an idea that " the coast is rising ;" but if by this phrase 

 we understand an integral upheaval of the rocky sea-floor, there is 

 no evidence to support the doctrine. And in places where the coast 

 is directly exposed to the ocean alone, surveys made under my own 

 orders show that no change has taken place for nearly 30 years, that 

 is, since the first revenue survey. 



The basaltic sea-floor, outside of the reefs and islands mentioned 

 (and from the coast itself north and south of tbem), descends by 

 gentle slopes, broken here and there by terraces, until at about 60 

 sea miles from the coast the " outer line of soundings" is marked by 

 depths, inside the line, usually of less than 100 fathoms, and outside 

 it in most cases of more than 200. This is a very rough description 

 of a matter deserving a fuller and better notice ; but for the purposes 

 of this paper, the " outer line of soundings" may be described as 

 marking a range of submarine u Ghats" about 600 feet high, forming 

 the western face of a plateau continuous with the flat parts of the 

 coast and descending from it, by gentle slopes and small scarps, at the 

 rate of about 10 feet to a nautical mile. We know little positively of 

 its material, but are justified from its outlir.es and position in sup- 

 posing this to be the Deccan trap, overlaid of course with marine 

 deposits. 



The Orders, Genera, and even Species of aquatic animals which pass 

 from the salt to the fresh w r ater are in places pretty numerous, and it ia 

 therefore convenient to take the whole area together in noticing them. 



The highest aquatic mammal of the Konkan is the Otter, which 

 inhabits all the creeks and streams and occasionally visits the sea, but 

 is not very common, and being a nocturnal beast and very shy is 

 seldom seen. It breeds in the hot weather. 



After it come the cetaceans, of which we know but little. The 

 Indian Borqual is known occasionally to visit the coast, and there 

 may be other large species. However, in a considerable experience of 

 the Konkan, I never saw a Whale spout in sight of shore but once. 

 It would be interesting if the experience of some of the officers of 

 the B. I. §. N. Company regarding this matter could be made 



