INTRODUCTION. 
Tre present volume is the first of the series of the new edition 
of the ‘Avifauna of British India,’ and, funds permitting, it is 
proposed to bring out about one volume every two years until 
the work is completed. 
It has been my endeavour in writing this volume to disturb as 
little as possible the classification adopted by Oates in the first 
edition but during the thirty-two years that have elapsed since 
his first volume was published, much scientific work has been done 
and many discoveries made which have rendered alterations 
imperative ; some of these, unfortunately, are of a drastic nature. 
In the first place, the trinomial system has been adopted—a de- 
cision which has added very greatly to the number of birds to be 
described, t.¢. to the total number of species and subspecies, 
though, on the other hand, it has reduced the number of species, 
for it has relegated to their proper positions as subspecies or 
geographical races many forms which have hitherto improperiy 
held the status of species. 
In using the trinomial system I have adhered to the follow- 
ing rules :— 
Forms, or groups of forms, have been named as specific when 
there are no forms known which directly connect them with other 
forms or groups of forms. 
Subspecies or geographical forms have been recognized when 
they differ in degree either in size, colour or some other 
characteristic from the forms with which they are most closely 
connected, yet, though linked with these forms by others which 
are intermediate, are themselves constant within some given area. 
VOL. I. B 
