INTRODUCTION. 



The 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 posfiible the classification adopted by Gates in the first 

 edition but during the thirty-two years that have elapsed since 

 his first volume was published, miicli scientific work has been done 

 and many discoveries made which have rendered alterations 

 imperative ; some ot these, unfortunately, are of a drastic nature. 



In the first place, the trinomial system has been adoptetl — a de- 

 (•ision which has added ver_> greatly to the number of birds to be 

 described, i.e. to the total number of species and subspecies, 

 though, on the other iiand, 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 improperly 

 held tlie status of species. 



In using the trinomial system I have adhered to the follow- 

 ing rules : — • 



Eorms, 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 geogiaphicul forms have been recognized when 

 they ditt'er in degree either in size, colour or some other 

 characteristic from the forms with which they are most closely 

 connected, yet, thougli linked with these forms by others w hich 

 are intermediate, are themselves constant within some given area. 



VOL. I. B 



