THE PALMS OF BRITISH INDIA AND CEYLON. 51 



To this sub-region are exclusively confined the following species : 

 Areca nagensis, Pinanga griffithii, P. hookeriana, Didymosperma nana, 

 D. gracilis and Plectocomia hhasyana. Of other species we find 

 Pinanga gracilis, Wallichia densijlora, Didymosperma nana, Caryota 

 urens, Caryota obtusa, Phoenix rupicola, P. acaidis, P. liumilis, 

 Licuala peltata, Livistonajenhinsia, Trachycarpus martiana, Calamus 

 erectus, C. flagellum, C. leptospadix, C. jloribundus, C. acanthospa- 

 ihus, C. gracilis, Dcemonorops jenkinsianus, Zalacca secunda. 



Western Burma includes the humid strip of land between the sea- 

 and the crests of the Chittagong and Arakan Hills, and separated by 

 the deltas of the Irrawaddy, Sittang, and other rivers, the coast of 

 Tenasserim down to Mergui. The mean temperature of Chittagong is 

 77°. April and May are about equally hot, viz., 81° and 82° and it 

 remains nearly uniform from April to the end of September, the 

 night temperature rising in the same measure as the day temperature 

 falls, until the daily range is reduced by one-half, more or less. The 

 highest temperature of the year occurs in April, or, more frequently 

 in May, and varies between 91° and 99°. In the cool season the 

 lowest temperature occurs as a rule in January, sometimes in February, 

 and varies between 45° and 52°. The diurnal range of temperature 

 in the drier seasons of the year does not exceed 23°. The humidity 

 of the air averages 80, and in the driest month, either February or 

 March, is as high as 70. At the height of the rains the humidity 

 averages 87 per cent, and upwards. The rainfall amounts on an 

 average to 106 inches and the number of rainy days to 122. '' The 

 position and configuration of Arakan and Tenasserim on the west 

 coast of the peninsula, with hill ranges running parallel with the coast, 

 expose them to the influence of the south-west monsoon of the Bay 

 of Bengal, in the same manner and as fully as are the Konkan and 

 Malabar to that of the Arabian Sea, and with a similar result, viz., 

 an excessive rainfall from June to September. In Arakan, however, 

 this rainfall is more prolonged than on the west coast of the Konkan 

 in the .same latitudes.' 5 (Blanford). Dense, evergreen forests cover this 

 tract of country, Dipterocarps, Oaks, Bamboos, Orchids, Palms, and 

 Ferns forming a conspicuous feature. In Chittagong occur Wallichia 

 densiflora, W. caryotoides, Calamus erectus, C. viminalis, C. tenuis, 

 C. guruba, C. gracilis, and Dcemonorops jenhinsiannus, in Tenasserim 

 Licuala longipes, L. speciosa, Calamus concinnus, C feanus, C. 



