WHITE WAGTAIL. 65 



or even seven in number, and vary much more than 

 those of the Pied Wagtail. I attribute this peculiarity 

 to the fact of the Pied Wagtail having a very restricted 

 geographical area, and being decidedly the youngest 

 species. They vary in ground colour from pure white 

 to very pale blue, spotted, freckled, and splashed with 

 grayish-brown and various shades of reddish-brown. 

 The underlying markings of the same general character 

 are various shades of gray. Occasionally a few hair-like, 

 nearly black streaks occur, notably on the large end. 

 The spots are sometimes small and distributed over the 

 entire surface ; at others they are chiefly collected in a 

 broad zone round the large end of the egg ; whilst 

 others, yet again, arc distributed in splashes and 

 mottlings over the entire surface. Average measure- 

 ment, the same as in the preceding species. Incubation 

 period the same. 



DIAGNOSTIC CHARACTERS : It is impossible to give 

 any character by which the eggs of the White Wagtail 

 may be distinguished from those of the Pied Wagtail ; 

 the range of variation is wider, and the markings are 

 richer and larger. The White Wagtail is easily identi- 

 fied by its slate-gray instead of black upper plumage 

 below the nape. 



