Dalgleish on North American Birds in Europe. 67 



here to mention that an extensive series of observations on migra- 

 tion, with reference particularly to the prevailing winds and weather 

 at the periods of such, are at present being carried on in Great 

 Britain, b}' Messrs. Cordeaux and Harvie-Brown, by means of returns 

 kept by the keepers of the various light-houses on its coasts, with the 

 sanction of the authorities, and with the co-operation of Herr Gatke 

 at Heligoland by means of his observations there, and from which 

 important results are expected. The first year's report is to appear 

 in the " Zoologist " for May of this year. 



I have not ventured, on the other hand, to enter into any dis- 

 quisition respecting the authenticity of the various records, but I 

 have stated the doubts which have been thrown on some of these 

 by others better qualified to give an- opinion. I have considered it 

 better to include such, with th& doubts alluded to stated, rather 

 than to omit these altogether, however well founded the latter 

 may be. 



I have had some difficulty in determining which species should 

 be included as North American birds, but, with two exceptions, I 

 have excluded all those which appear in Bonaparte's " Comparative 

 and Geographical List of the Birds of Europe and North America " 

 (1838) as common to both continents. These exceptions are Surnia 

 funerea and Clangida histrionica, the former being now considered, 

 as a distinct species from -S*. %dida, the European Hawk-Owl, and 

 the latter I have retained, as Iceland is the only part of Europe 

 where it may be said to be a permanent resident. I have also 

 added a note of the occurrence of three species which, although not 

 strictl}' North American, are yet oceanic in their distribution, and 

 thus occur more or less irregularly on the shores of that continent, 

 and whose appearance, moreover, in Europe is worthy of notice. 

 These are Sterna fidiginosa and S. anoestheta, the Greater and 

 Lesser Sooty Terns, and Anous stolidus, the Noddy Tern. 



The various countries which have been visited by the different 

 species are placed in the same sequence throughout, and the occur- 

 rences in chronological order. The names of these countries are, 

 for easy reference, printed in heavier type, and the date of each oc- 

 currence, so far as known, is placed at the end of the record in simi- 

 lar type. 



In some cases I have avoided general notices by authors where 

 no particulars are given of the locality or date, believing that such 

 are of no practical value. The references given are to the original 



