SOUNDINGS OF ADJACENT SEAS 321 



but the Archipelago seems capable of division into two groups, 

 each standing on a loo-fathom bank. 



The northern of these consists of the compactly-situated central 

 islands, and possibly Kar Nicobar, and is separated from the 

 southern (Great and Little Nicobar and the adjacent islets, all 

 perhaps surrounded by a 50-fathom line) by a channel with 

 approximate depths of 200 fathoms. 



The Nicobars stand at the termination of a rooo-fathom bank, 

 projecting from the Arakan Yoma Peninsula, and from thence 

 also curving east and south towards Sumatra, thus enclosing a 

 long tongue of deep sea, over 1000 fathoms deep, that is connected 

 with the Indian Ocean by the channel separating them from 

 Sumatra. 



This deep sea that surrounds the islands everywhere but on 

 the north, shows that, so far as need be taken into account for 

 present purposes, they have never been connected with the Malay 

 Peninsula or Sumatra — a condition that is further shown by the 

 almost total absence of any members of the Malayan fauna — 

 although they may at one time have been a prolongation of 

 the Arakan Hills. 



"It cannot, however, be asserted that this latter theory of 

 connection derives, pj'imd facie, much support from a consideration 

 of their fauna ; and if they ever were in uninterrupted communica- 

 tion with the Arakan Hills it must apparently have been at an 

 immensely distant period, for not only are all the most character- 

 istic species of the Arakan Hills, as we now find them, absent from 

 the islands, but the latter exhibit a great number of distinc-t and 

 peculiar forms, constituting, where the ornis is concerned, con- 

 siderably more than one -third the number known." — Hume, 

 Stray Feathers, vol. ii. 



From the above details, it is to be inferred that not only 

 have the Nicobars — if ever in connection with the mainland — 

 been longest separated, but that they have also been discon- 

 nected among themselves for a great extent of time. At a 

 later period the Andamans were cut off from the continent, and 



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