144 TERRESTRIAI, TAMIUES OV II KMIITKRA-Ii KTKROl'TKRA 



to Indian Tihi't and one to Indian Tibet and tlie Southern ilinialaya. Moreover, it is 

 probable that were a male of the species of Sticto/^lnira c)l)tained availaljle, tliis tno would 

 be found to l)e an endemic species. It tlierefore appears that at least liaif tlie species of 

 the region are peculiar to tlie I liinalayan and Karal<i)rum ranges, and that the High Taniir 

 though richer in species is much poorer in ]ieculiar forms. This is ])robably to l)e explained 

 by the fact that, while in the Pamirs after the Quaternary Glaciation a number of routes 

 for recolonisation were open (Reinig, 1932), putting the high regions into easy communi- 

 cation with the richest Ilcteropterous fauna in the Palaearctic region (cf. Kiritshenko, 

 1931 a), in Indian Tibet the only migration nnites were from the North over extensive 

 mountain ranges and deserts, from the humid south and west where the Sub- Himalayan and 

 Kashmirian forest fauna is apparently ecologically unsuited to penetrate into very elevated 

 and semi-arid regions, and from the east where a restricted pre-glacial high-altitude fauna may 

 have survived in the less glaciated parts of western Tibet jimper. The material available 

 suggests that certain forms such as Nysitis cricac obsciinitus and Microplax hissaricusis 

 belong to a Central Asiatic element that has entered by the northern route, while the endemic 

 genera and perhaps some or all of the endemic species represent a migration from hypothet- 

 ically unglaciated regions of the Tibetan plateau, where a fauna of undoubted Central Asiatic 

 origin survived and differentiated at a time when the greater ])art of the Karakorum and 

 Western Himalaya were heavily glaciated and quite uninhaljitable. Without some such 

 hypothesis it seems impossible to explain the large proportion of endemic forms in a region 

 that has suffered so much glaciation in relatively recent times. 



Osborn Zoological Laboratory, 

 Yale University, 

 July 18, 1934. 



