SURVIJy SEASON IN THE NICOBAR ISLANDS. 
981 
it'd across their mouths close to where they open into a lai'ge mangrove swamjr 
on the east side. Traces of these bunds can still be seen. The low-lying area 
forms an excellent snipe-gromid during the cold weather, and one could nearly 
always depend on finding several couple of the Pin-tail Snipe, Gallinago 
stenura. In addition to these comparatively large nullahs, numerous small ravines 
run down from the higher gromid to the sea. During the rains these become 
true water courses and serve as a habitat for three species of operculate fresh 
water molluscs belonging to the Neritidae and Melaniidae. It is interesting to 
note that such widely distributed non -operculate genera as Limnoea and 
Planorbis (including Indoplanorhis) are conspicuous by their absence. Even the 
only two land snails that I came across belonged to operculate genera. In 
view of the amount of rain that falls annually, namely some 120 inches, and 
its comparatively miiform distribution throughout the year — March and April 
being the only dry months — this marked predominance of operculate forms is 
■extremely interesting . It cannot be accoimted for by prolonged periods of 
•drought that would tend to kill off all non-ox>erculate forms, and it suggests that 
it is this character that has facilitated the transport of these forms from 
<li.stant coasts of Burma or Sumatra. 
In one low-lying area, through which a small stream ran a tortuous course, 
I found several examines of Palcetnon and two specimens of what appears to be a 
species of Caridina : in addition a few young fish, Eleotris sp., were also obtained. 
AH these ravines served as a habitat for the Pin -tail Snipe, Gallinago stenura, 
and not infrequently one saw the White-breasted Water-hen, Amaurornis 
insularis Sharpe, but the numbers present were always small. 
All along the eastern and western sides of Nankauri and the west side of 
Camorta, where the geological formation consists of true rock, and in smaller 
patches in other parts of the islands where the soil is suitable, one finds a dense 
growth of primaeval jungle with occasional cocoanut palms and Pandanus trees, 
the whole laced together with creepers that in places form a dense green blanket 
spreading from tree-top to tree-top, while on the groimd level a thick growth of 
rattan cane and creeping bamboo renders progress almost impossible. The 
Pandanus tree appears to be able to grow in almost any locality. I have already 
mentioned that it is almost the only tree that will grow on the sterile clay-land 
— a power that it shares with the Casuarina — and near the entrance to Expedi- 
tion Harbour several small and stunted examples are maintaining a precarious 
foot-hold on a narrow ledge of rock only a few feet above the sea. It is in the pri- 
maeval jungle or in special plantations that we find the enormously tall Pandanus 
trees that Roxburgh* refers to in his work on Indian plants. He there gives the 
height of these trees as thirty-five to forty feet, but in the jungle I have seen them 
considerably taller than this and, indeed, there seems to be no limit to which they 
cannot attain. The extension upwards seems to be an adaptation to the surround- 
ings, for unless the tree can rise to the level of or above the immensely tall 
forest trees of the primaeval jmigle it will be completely deprived of smrlight and 
hence Avill die. 
In the neighbouring island of Kachal numerous monkeys are to be fomid, but 
I never saw any nor so far as I know have any been recorded from Camorta or 
Xankauri. In these islands the chief inhabitants of the primaeval forest are 
enormous numbers of Pigeon. The commonest of all is the Nicobar Imperial Pi- 
geon, Carpophaga cenea insularis (Blyth) ; though very often difficult to see owmg 
to the thickness of the foliage, its deep low coo betrays its presence everywhere. 
Associated with these birds, and hardly to be distinguished from them until they 
have been shot and examined carefully, are a few examples of the Andamanese 
Wood-Pigeon, Alsoco^nus 2i(flumhoides (Hume). Ear less common than the 
• W. Roxburgh, “ Flora Indica or Descriptions of Indian Plants” i) 707 
Calcutta, 1874. ’ 
