Botany of the Tenasserim Provinces. 73 



Calcareous hills of a peculiar form occur, scattered here and 

 there, but are most common about Moulmein, especially at 

 Kogoon, on the Salveen, the habitat of Amherstia nobilis. At 

 Trochla, on the southern side, one of these hills occurs of 

 great height, forming a precipice of perhaps 3,000 feet. These 

 peculiar formations arise abruptly from plains to the height 

 of generally 400 feet. 



Their ridges are exceedingly sharp and rugged, and very 

 generally they are sheer precipices and totally inaccessible. 

 Their vegetation is scanty, but that at their base is exceed- 

 ingly rich. They are, without exception, excavated, and fre- 

 quently perforated, so as to form internal caves which have 

 been at one time the favourite places of Burmese worship. 



The birds' nest rocks, from which a revenue is derived at 

 Tavoy, exceeding 10,000 rupees per annum, and at Mergui 

 5,000, belong to the same formation. They likewise rise 

 perpendicularly through and from the sea, and are still more 

 bleak and rugged from their greater degree of exposure and 

 exceedingly scanty vegetation, chiefly indeed of a species of 

 Ficus. With the exception of Casuarina muricata, which 

 occurs ill abundance from Chittagong to Yeayla, near Tavoy, 

 there is no plant which impresses a peculiar feature on the 

 landscape, scarcely excepting several species of bamboo, which, 

 in addition, are associated with a local flora. 



The remaining tracts are either of mangroves, or Gramineae 

 and Cyperaceae ; the plains and the hills are covered from 

 top to bottom with an exceedingly rich, varied, and magni- 

 ficent vegetation. 



With respect to the probable number of species known, 

 Dr. Wallich's Catalogue contains about 1,650, of these the 

 majority perhaps are from the Burmese dominions. My col- 

 lection from Moulmein and Mergui, made during a residence of 

 fourteen months on the Coast, amounts to about 1,700 species; 

 of these about 1,300 are from Mergui, which may be consi- 

 dered new ground. Taking this into consideration, the ma- 



