PRELIMINARY NOTE 



Numerous incidental references have already, in the preceding 

 pages, been made to the depth and temperature of the Indian 

 seas, and more exact statements on the same subject will be 

 found in one of the Appendices : it may not be amiss, however, 

 to prefix to this short review of the local deep-sea fauna a brief 

 summary and iteration of the matter. 



The Andaman Sea^ which is the basin enclosed by Burma and 

 the Malay Peninsula on the north and east, and by the Andaman 

 and Nicobar Islands on the west, has, as far as our present 

 knowledge goes, a maximum depth of about 1600 fathoms, but 

 the average depth of its open parts is about iioo fathoms. The 

 average temperature of its surface waters is about 80° Fahr., but 

 the temperature of its depths below 1000 fathoms is somewhere 

 about 41° Fahr. 



The Bay of Bengal is that great reach of the Indian Ocean 

 whose waters wash the shores of Ceylon and British India from 

 the meridian of 80° E. eastwards as far as the Andaman-Nicobar 

 chain. It is a vast submarine plain, shelving very gradually to a 

 depth of 2300 fathoms at its mouth, its unbroken monotony 

 being relieved, so far as we know, by only one elevation. This 

 elevation, which may be compared to a great isolated hill 5820 

 feet high, is known, after Commander Alfred Carpenter, R.N., 

 as Carpenter's Ridge: its summit, which rises to within 1370 

 fathoms of the surface, lies about 200 miles west by south of 

 Great Nicobar Island. The average temperature of the open 



225 N p 



