THE ZOOLOGICAL DIVISIONS OF SIKHIM, 695 



' more cosmopolitan in their range, and I do not find that the middle 

 ' zone contains anything like the same proportion of peculiar species 

 6 or genera of Lepidoptera in proportion to the lower one, as it does 

 ' in the case of birds and plants. I also notice that the upper zone, 

 ' especially in the outer hills, where the rainfall is much heavier 

 1 than in the interior, is much poorer both in abundance and variety 

 4 of species than might be expected from its great extent and 

 ' elevation, and from the great number and variety of species which 

 ' are found in the adjoining regions of Turkestan and China. This, 

 ' however, may be accounted for by the extreme moisture of the 

 1 climate, and the prevalence of rain and mist during the summer 

 ' or rainy season, which lasts almost without intermission from May 

 ' till October. It is also probable that a better knowledge of the 

 1 drier valleys and mountains of the interior at an elevation of 

 ' 9 — 14,000 ft. will add many new species to the few which we at 

 ' present have obtained through our native collectors, as it must 

 ' be remembered that no European has hitherto collected insects 

 " systematically at a higher elevation than 12,000 ft. in the Eastern 

 ' Himalayas, and that the interior valleys are as yet practically 

 ' untouched." (1. c, pp. 272, 273.) 



