JOURNAL 



OE THE 



ASIATIC SOCIETY OF BENGAL. 



Part II.— PHYSICAL SCIENCE. 



No. III.— 1876. 



X. — A Sketch of the Vegetation of the Nicobar Islands. 



By S. Kttez. 



(Received July 27th ; — Eead August 2nd, 1876.) 



(With Plates XII and XIII.) 



The Nieobars form a link in the chain of islands that stretches up from 



Sumatra to the Arracan Yomah, and they are in all probability the remnants 



of a mountain-range that connected Sumatra (and more especially the Nias 



islands, where the same sandstone prevails as that of the Andamans and 



Arracan) and Arracan at a time when the sea covered the vast alluvial 



plains of the Ganges and the Indus, thus rendering Hindustan an island 



subsequently to its probable connection with Africa. 



Geologically, the Nieobars are divisible into two groups, the southern and 

 the northern. The former comprises Great and Little Nicobar with the adja- 

 cent islets and Katchall. It is characterised by the predominance of calcareous 

 sandstones (Brown-coal formation) . The northern group includes Nankowry, 

 Kamorta, Trinkut,* Teressa, Tillangchong, Karnicobar, and the small islands 

 near them. Alluvial deposits and plutonic rocks are the conspicuous feature 

 here. This geological division admirably coincides with the general botani- 

 cal appearance of the respective islands. f While the islands of the southern 



* Trinkut is not entirely composed of raised coral-reefs as Dr. Hochstetter has 

 stated, but has grass-heaths in the centre, the presence of polycistina-clay being thus 

 indicated. It is a very fiat island, barely 50 feet, above sea-level in the interior. 



t This sketch relates to the islands of Katchall and Kamorta only, sickness 

 having prevented me from extending my explorations to the other islands. A review 

 of the more interesting peculiarities of the Nicobar vegetation is to be found in 

 Trimen's Journal of Botany, 1875, p. 321 sqq. 

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