INDIA 301 



as a whole, is distinctly inferior to the Indian. Another char- 

 acteristic group of the Indo-Malay region is Amphidromus^ with 

 its gaudily painted and often sinistral shell ; the genus is entirely 

 absent from China proper and Japan, where its place is taken 

 by various small forms of the Buliminus group. Fresh-water 

 Mollusca, especially the bivalves and operculates, are far more 

 abundant in the Chinese sub-region than in the Indo-Malay. 



(1) The Indo-Malay Sub-region. — {a) The Indian Province 

 proper includes the peninsula of Hindostan, together with Assam 

 and Upper and Lower Burmah. To the east and extreme north- 

 east, the boundaries of the province are ill-defined, and the fauna 

 gradually assimilates with the Siamese on the one hand and the 

 Chinese on the other. Roughly speaking, the line of demarca- 

 tion follows the mountain ranges which separate Burmese from 

 Chinese territory, but the debatable ground is of wide extent, 

 and Yiinnan, the first Chinese province over the border, has 

 many species common with Upper Burmah. 



The gigantic ranges of mountains which bound the sub- 

 region to the north-west and north limit the extension of the 

 Indian fauna in those directions in a most decisive manner. 

 There is no quarter of the world, even in W. America, where a 

 mountain chain has equal effect in barring back a fauna. In 

 the north of Kashmir, where the great forests end, there is a 

 most complete change of environment as the traveller gains the 

 summit of the watershed; but Kashmir itself distinctly belongs 

 to the Indian and not the Palaearctic system. The great desert 

 to the south of the Punjab is equally effective as a barrier 

 towards the west. 



The Mollusca of India proper include a very large number of 

 interesting and remarkable genera. India is the metropolis of 

 the great family of the Naninidae, or snails with a caudal mucus- 

 pore, which are here represented by no less than 14 genera and 

 over 200 species. The genera Macrochlamys^ Sitala^ Kaliella^ 

 AriopTianta^ Grirasia, Austenia, and Durgella are at their maxi- 

 mum. Helix is scarcely represented, containing only about 30 

 inconspicuous species (leaving Ceylon out of account). Bidimi- 

 nus is abundant, especially in the north. The Stenogyridae are 

 represented by G-lessula, which is exceedingly abundant in India, 

 but has only a few straggling representatives in the rest of the 

 Oriental region. Among the Pupidae is the remarkable form 



