Xiv INTRUDL'CTIOy. 



DiSTRIBUTIOK. 



The status and distribution of each species is given in two 

 paragraphs, the first dealing with the British, the second with 

 the exotic range. For the British distribution of the Passeres 

 Mr. Eagle Clarke is responsible, while the exotic distribution 

 has been drawn up by Miss E. V. Baxter and Miss L. S. 

 Rintoul. To these two ladies the Committee wish to tender 

 their best thanks for the time and trouble they have taken 

 over the matter. The distribution, both British and exotic, of 

 the non-Passerine birds has been undertaken by Mr. Ogilvie- 

 Grant. 



Doubtful British Species. 



Species, the occurrence of which in the British Islands, is, 

 in the opinion of the Committee, not positively authenticated 

 have been relegated to Appendix I. 



Summary of British Birds according to their Status. 



The British Birds recognised in the present edition of 

 the List number 475 in all. Of these 188 are regular 

 breeding-birds and 286 are non-breeding, and one is extinct. 

 The List may be further subdivided into the following 

 categories, though it must always be borne in mind that 

 such classifications as these are necessarily not stringent, 

 and there are always some species which do not fit exactly 

 into any of the groups : — 



1. RESIDENTS.— All birds generally found in the British 

 Islands throughout the year are included in this 

 category, though many of these are partially migratory, 



