NORTHERN TIT. 215 



species, because I think I have always fouml a constant 

 difference between them, both in structure and habit. 

 AYith the exception of tlie immature dress, I have 

 always found a difference in the appearance of the 

 black colour on the head, the white on the cheeks, 

 the grey brown on the back, as well as the broad 

 white edges on the wing feathers. Since I have ob- 

 served this, I can, at a tolerably long distance, 

 distinguish P. horcalis by the white colour of the 

 cheeks, which extends far back; and other naturalists 

 who have been with me on excursions have done the 

 same. The black colour on the head of P. borealis I 

 have always found different in the nearly total absence 

 of metallic gloss, whereas P. palustris has always this 

 distinct. In the summer plumage I have found in 

 palustris the grey brown colour on the back darker 

 than in borealis in the same dress, and I have always 

 found the former wants the white edges on the outer 

 webs of the primaries. Nearly always I have found 

 the wings of borealis shorter than in palustris, and 

 the exceptions are so few that the fact appears to be 

 normal. Degiand's remarks about the colour of the 

 legs have evidently been made from stuffed specimens, 

 and in all such the legs of this, as other birds, become 

 darker. Anyone Avho has chanced to hear P. jyalustris 

 and P. borealis together, can easily distinguish that 

 the note of the latter h both sharper and rougher. 

 The note, 'tit, tit,' is sharper, and that which follows 

 it, 'tiah, tiah,' is rougher and more lengthened. On 

 this I lay great weight. 



'*Tn Scania I have never seen P. borealis otherwise 

 than in fir forests, and here (Upsula) I have never 

 seen P. palustris except in leafy plantations, parks, 

 gardens, etc. Here borealis, on the contrary, is found 



