BOMBAY NATURAL HISTORY SOCIETY'S 

 HAMMAL SURVEY OF INDIA, BURMA AND CEYLON. 



Report No. 23. Sikkim and Bengal Terai. 



With a Map. 



By R. C. Wroughton. 



Collection ... ... No. 23. 



Locality ... ... Sikkim and Bengal Terai. 



Date October 1914— April 1915. 



Collected BY ... ... Mr. C. A. Crump. 



Earlier Reports ... ... No. 1, East Khandesh, Vol. XXI, p. 



392, 1912 ; No. 2, Berars, Vol. XXI, p. 820, 1912 ; No. 3, 

 Cutch, Vol. XXI, p. 826, 191i; ; No. 4, Nimar, Vol, XXI, 

 p. 944, 1912 ; No. 5, Dharwar, Vol. XXI, p. 1170, 1912 ; 

 No. 6, Kanara, Vol. XXII, p. 29, 1913; No. 7, Central 

 Provinces, Vol. XlLLl, p. 45, 1913; No. 8, Bellary, Vol. 

 XXII, p. 56, 1913 ; No. 9, Mysore, Vol. XXII, p. 283, 1913 ; 

 No. 10, Kathiawar, Vol. XXII, p. 464, 1913 ; No. 11, Coorg, 

 Vol. XXII, p. 486, 1913 ; No. 12, Palanpur, Vol. XXII, p. 

 684, 1913 ; No. 13, South Ceylon, Vol. XXII, p. 700, 1913 ; 

 No. 14, N. Shan States, Vol. XXII, p. 710, 1913; No. 15, 

 Kumaon, Vol. XXIII, p. 282, 1914; No. 16, Dry Zone, 

 Central Burma and Mt. Popa, Vol. XXIII, p. 460, 1915 ; 

 No. 17, Tennasserim, Vol. XXIII, p. 695, 1915 ; No. 18 

 Ceylon, Vol. X^IV, p. 79, 1915; No. 19, Bengal, Vol. 

 XXIV, p. 96, 1915 ; No. 20, Chindwin River, Vol. XXIV, 

 p. 291, 1916; No. 21, Gwalior, Vol. XXIV, p. 309, 1916; 

 No. 22, Koyna Valley, Vol. XXIV, p. 311, 1916. 



This Collection contains representatives of two markedly distinct 

 faunas, viz., that of the Gangetic Plain and that of the Himalayas. 

 In this respect it somewhat resembles the collection from Kumaon, 

 but the dividing line seems to be more sharply marked in the pre- 

 sent case, and the Himalayan species show signs of colour relation- 

 ship with the more eastern tj^pes. Thiis T^Zjjes hengalensis and 

 Funamhulus ijennanti are characteristic of the plains fauna while 

 Vulpes montana, Ochotona and Microtus are exclusivel}^ Himalayan, 

 the Ochotona however is different from that in the Kumaon Collec- 

 tion, which is more closely related to the form of the Western 

 Himalayas. 



The general configuration of this part of the Himalayas is too 

 well known to require detailed description but I should like to call 

 attention to the sudden rise in altitude which seems to be reflected in 

 the abrupt change in the fauna that I have noted above. Up to 

 and beyond Siliguri the general altitude is only about 200 feet, yet 

 ■Ghoom and Darjeeling more than 7,000 feet, are within 15 miles as 



