284 D. Prain — The Vegetation of the Coco Group. [No. 4, 



13° 45' N., consisting of several large islands that are separated by straits 

 and channels which, with the exception of a passage 30 miles wide 

 and about 100 fathoms deep between Rutland Island and Little Andaman, 

 are all very narrow and usually quite shallow. Further south we find 

 in the same chain the Nicobar Islands ; these, separated by wider inter- 

 vals than the members of the Andaman Group are, extend from 6° 45' 

 to 7° 15' N. Besides being wider, the passages between the individual 

 islands here are much deeper and the main channels between the 

 Andamans and Nicobars on the one hand, and between the Nicobars 

 and Sumatra or the Nias Islands on the other, in place of being under 

 150 fathoms deep, give soundings of 500, 750, and even 900 fathoms. 

 There is, however, along the line from Little Andaman to the island of 

 Simalu or to Acheen Head an undoubted ridge, for the floor of the Sea 

 of Bengal to the westward is 2,000 fathoms deep, and that of the Andaman 

 Sea to the eastward is in some places at as great a depth. Whether 

 any portion of the now submarine sections of the southern, or Nicobars half 

 of this ridge has ever been subaerial it is difficult to say but it seems 

 likely from its present physiographical configuration that tlie most recent 

 land connection must have been between the northern or Andaman half 

 of the ridge and the adjacent Indo-Chinese district of Arracan. 



Table Island, the most northerly member of the Coco group, and 

 lying 45 miles north of Landfall, is about a mile across and is rather 

 longer than broad, with a considerable outlying islet, Slipper Island, 

 at its north-west corner ; southward, across a strait about two miles 

 wide, lies the Great Coco some 9 miles long from north to south and 

 about 2| across at the widest part with several small islets off both its 

 east and west coasts and with a very considerable outlying islet, Jerry 

 Island, at its southern extremity ; finally, some 6 miles south-west of 

 Great Coco, and 30 miles north of Landfall, is the Little Coco about 2|- 

 miles long from north to south and j to ^ a. mile wide. 



Through the kindness of Capt. Hoskyn, R.N., the writer, in com- 

 pany with Dr. Alcock of H. M. I. M. " Investigator," has been able 

 to visit the group on two occasions. On Nov. 30th and Dec. 1st, 1889, 

 Table Island was examined. On Dec. 2nd, 1889, a naturalist's party, 

 which the writer was privileged to join, landed on Great Coco and re- 

 mained encamped on a small cleared hill in its north-eastern peninsula 

 until Dec. 8th. From Nov. 14th till Nov. 23rd, 1890, a similar party, of 

 which the writer again was a member, was encamped on a sandy spit 

 covered with coco- nut trees at the south end of the island ; while be- 

 tween Nov. 26th and Nov. 30th, 1890, the Little Coco was examined. 



On Table Island is situated the well known lighthouse of this 

 name and the western slopes of the main island as well as most of Slip- 



