Family MOTACILLIDAE. 



Motacilla flava L. — Blue-headed Wagtail. 

 Motacilla flava rayi (Bonaparte). Yellow Wagtail. 



(Plate 32, fig. a-e). 

 (Snouckaert: Avifauna Neerlandica, p. 26-27, Nos. 56 and 58). 



Colour of surface of shell: 



Colour of spots: 

 Average dimensions: 

 Average weight of shell: 

 Texture of shell: 

 Shape : 

 Nest: 



Site of nest: 



Number of eggs: 

 Breeding season: 

 Duration of incubation: 

 Remarks : 



yellowish white; brownish yellow; greenish ; 

 reddish. 



darker variegations of the ground colour. 



18.7 X 13.8 millimetres. 



0.106 gram. 



has no characteristic of its own. 



usually short ovoidal. 



consists of vegetable materials, lined with 

 seed down and horsehair, sometimes also 

 with feathers. 



on the ground in a little hollow, especially 

 on the banks of ditches and trenches in 

 arable land and meadows. 



5-6. 



June— July, 

 about 13 days. 



one of the types shows in colour and mar- 

 kings as well as in size and shape a marked 

 resemblance to certain eggs of Calamodus 

 schoenobaenus. 



M. flava and M. flava rayi present no oological 

 points of difference. * 



