or Willow-Warblers. 69 



Where the dimensions given in the following descriptions 

 do not show so much variation^ it may arise from my not 

 having been able to procure access to a sufficiently large 

 series. 



In order satisfactorily to determine the various species of 

 this genus^ an acquaintance with the birds in a state of nature 

 seems more than ordinarily necessary ; and this is probably 

 the reason why this group has not been brought into better 

 order by our cabinet ornithologists. 



The following attempt to reduce this refractory genus into 

 something like order is the result of the comparison of about 

 four hundred skins from the collections of the British Museum^ 

 Lord Tweeddale^ Canon Tristram^ Messrs. Dresser, Swinhoe, 

 Brooks, von Homeyer, the Indian Museum, and my own 

 collection. 



I am especially indebted to my friends, Mr. H. E. Dresser 

 for assistance in Avorking out the intricate details of the syn- 

 onymy, and to Mr. W. E. Brooks for skins of various Indian 

 species, wdiich have been carefully compared with Blyth's 

 types in the Calcutta Museum. 



In the synonymy I have carefully avoided the pedantry of 

 a long catalogue of useless references ; and I have endeavoured 

 to make the descriptions of the birds as short and as easy of 

 comparison as possible. Much remains to be done in the geo- 

 graphical distribution ; and doubtless a few years^ researches 

 may detect many errors in, and make some additions to, our 

 present knowledge of this interesting group of birds. 



1. Phylloscopus borealis (Blasius). 



Sylvia {Phyllopneuste) eversmanii, Middendorff, Sib. Reise, 

 p. 178 (1851, nee Bonap.) ; Radde, Eeisen im Slid. v. Ost- 

 Sibir. ii. p. 263 (1863, nee Bonap.). 



Phyllopseustes eversmanii, Homeyer, Cab, Journ. f. Orn. 

 1872, p. 202 (nee Bonap.). 



Phyllopneuste borealis, Blasius, Naumannia, 1858, p. 313. 



Phyllopseustes borealis, Meves, Cab. Journ. f. Orn. 1875, 

 p. 429. 



Phylloscopus sylvicultrix, Swinhoe, Ibis, 1860, p. 53. 



