INTRODUCTION. xvii 



British Islands, after the doubtful ones have been rejected, is still 160, of 

 which 97 have probably visited us from Europe, 45 from America, and 18 

 from Asia. There is no reliable instance on record of any bird whose 

 breeding-range is confined to Africa ever having visited our shores. 



The total number of birds which are either known to breed in Europe 

 or are regular winter visitants is probably about 500. Of these, as we have 

 stated, 222 are residents in the British Islands, either in winter or summer, 

 and 97 are included in the list of accidental visitors, leaving only 180 

 European species which have not yet paid us a visit. The number of 

 accidental visitors to Europe probably does not exceed 90 ; of these about 

 60 have visited our islands, leaving only 30 birds which, so far as is known, 

 are accidental visitants to the continent alone. 



Of the resident British birds one species only, the Red Grouse, is 

 peculiar to our islands ; and one other, the British Coal Tit, is subspecifi- 

 cally distinct from its continental allies. 



It is necessary to say a few words on the vexed question of 



NOMENCLATURE. 



To understand the complications of the case let us take, as an example, 

 the synonymy of the Cliffchaff, from the ' Catalogue of the Birds in the 

 British Museum/ In order to give an index to the literature of this bird 

 no fewer than seventy-six references to the works of ornithologists are 

 given. An analysis of these gives the following result : The number of 

 specific names applied to the Chiffchaff by the writers quoted is fifteen. 

 Of these we may at once dismiss twelve, one of which only occurs four 

 times, one only three times, two only twice, and eight only once. We 

 have now three names left to choose from, dating as under : 



1787. hippolais (Linn, apud Lath.) 8 times 



1802. rufus (Becbst. ex Briss.) 41 



1817. collybita (Vieill.) 8 



It is obvious that the second name in the list is the one which ought, if 

 possible, to be used. Let us first examine how many generic names have 

 been applied to our bird ; no fewer than nine. To these, however, we 

 must add the generic terms which have been applied to other species of 

 the genus. After eliminating those names which are obviously blunders, 

 we have the following left : 



1766. Motacilla (Linn.). 



1769. Sylvia (Scop.). 



1802. Asilus (Bechst. nee Linn.). 



1816. Ficedula (Koch nee Cuvier). 



1817. Trochilus (Forster nee Linn.). 

 1826. Phylloscopus (Boie). 



1829. Sibilatrix (Kaup). 

 VOL. i. b 



