NOTES ON INDIAN TIMELIIDES AND THEIR ALLIES. 47 



A YQvj interesting fact, which I have not seen mentioned before, 

 is that although the Timeliides are so well represented in Burma and 

 Malay States, none have been recorded from the Andaman and 

 Nicobar Islands, obviously showing that these islands must either be 

 of recent formation, or had no connection with the mainland since 

 the appearance of this vevj large sub-order birds. 



Whilst working up the distribution of this fascinating group, I 

 was greatly struck by the manner in which species in certain locali- 

 ties were liable to variation. I soon found that by taking specimens 

 and grouping them according to these different localities, any dif- 

 ferences at once became apparent. In the hills these areas are more 

 or less well marked, in the plains the distribution is not so easy, or 

 my knowledge of the physical geography at fault. 



For some unaccountable reason, some species extending over a 

 wide area, seem to take every opportunity to vary, so we find geo- 

 graphical races, wherever there is any isolation. Whilst other 

 species occupjdng practically the same area, show hardlj;^ any varia- 

 tion whatever. 



All birds are more or less restricted to certain elevations, some 

 being entirely " Plains-dwellers," never ascending the hills to any 

 great height, whilst others are only found in the hills at certain 

 altitudes. A very curious fact, which I have never seen accounted 

 for, is the remarkable way in which, certain birds are only foijnd at 

 great heights in the Himalayas, occur at much lower levels in Assam 

 and Burma, 



It is also a well-known fact that species inhabiting both 

 a very dry and a damp locality differ in colour. Birds from 

 the former being paler, whilst those from the latter are darker 

 and more highly coloured. 



Another interesting fact noticed is that amongst species liable to 

 variation and which have a wide distribution (and represented by 

 numerous races) very often the sub-species furthest apart geogra- 

 phically, that is at the ends of the chain or extremities of the 

 " horse-shoe " resemble each other far more closely than those near 

 together and often are hardly separable. 



This is well illustrated in the " Scimiter-Babblers." Pomatorhi- 

 nils erythrogenys erythrocjenys, Vigors, from the N. W. Himalayas, 

 is only separable in size from P. e. imberhis, Salvadori, from Tenas- 

 serim ; (both these races are noticeable for having pure white 

 unstriped breasts). Intervening we have the following well-marked 

 sub-species, P. e. ferrugilatus, Hodgson, from Sikhim, which has the 

 breast almost entirely grey : in Assam P. e. macclellandi, Jerdon, 

 and in Yunnan and North-East Bm-ma P. e. cjravivox, David, both of 

 of which have boldly striped breasts ; and no doubt, connecting 

 links exist grading from one sub-species into the other, showing 

 that there is really only one species, which is represented by 



