or Willow -Warblers. 93 



accordingly splits P. colly bita (then generally called rufus) into 

 P. rufus and P. brevirostris. I have repeatedly shot both forms 

 of P. collybita, and have no doubt of their identity^ being unable 

 to detect any diiierence in their notes or habits. With P. 

 trochilus, however, the case is different. So far as my ex- 

 perience goes (and I have examined some hundreds of skins), 

 the second primary in this species is constantly intermediate 

 between the fifth and sixth. When I was in the valley of the 

 Petchora in 1875, just before we entered the delta of that 

 great river, I heard the note of a small Warbler resembling 

 the sound tzzzk, not unlike the spitting of a cat. Feeling 

 perfectly convinced that it proceeded from a bird with which 

 I was unacquainted, I chased it on the banks of the Petchora, 

 heard it repeatedly utter its extraordinary note, and finally shot 

 it. It tm-ned out to be a female of a species nearly allied to P. 

 trochilus, but with the second primary intermediate in length 

 between the sixth and seventh. The bastard primary Avas 

 much smaller than usual; and in the general colour of the 

 plumage there was an absence of the usual yellow tinge both 

 above and below, as is exceptionally the case with P. trochilus 

 in extreme summer plumage in high latitudes. Not liking 

 to make a new species on somewhat slender grounds from a 

 single example, I did not describe it (Ibis, 1876, p. 216). 

 Turning up Tristram's description of P. major, I concluded 

 my bird to belong to it, and to be a somewhat doubtful 

 species, until I visited Heligoland last autumn. Gaetke then 

 pointed out to me in the collection of birds in his studio a 

 " Laubvogel " much greyer on the back and whiter under- 

 neath than P. trochilus. He told me that he had been, at 

 some trouble to shoot it in his garden, because its note was 

 so different from that of P. trochilus. It turned out to be a 

 male. The length of wing and of bastard primary agree with 

 those of P. trochilus female, but are smaller than the usual 

 size of P. trochilus male. The second primary is interme- 

 diate in length between the sixth and seventh. A second 

 example having thus come under my notice, I am inclined to 

 think that Phylloscopus major of Tristram may turn out to 

 be a good species after all ; but since the name major can- 



