NON-INDIGENOUS BRITISH BIRDS. 7 



not known to exceed four in number. They vary from 

 pale blue to white with a tinge of green or blue in 

 ground colour with dark-brown and paler brown surface 

 spots and specks, and underlying markings of a similar 

 character, but violet-gray in colour. As a rule the 

 markings are most thickly distributed on the large end 

 of the e^gg, round which they generally form an irregular 

 zone. Average measurement, 78 inch in length by '55 

 inch in breadth. Incubation presumably lasts fourteen 

 days, but whether performed solely by the female is not 

 known. 



Diagnostic characters : It is impossible to give 

 any character by which the eggs of this species can be 

 distinguished from those of the Greenfinch and the 

 Common Crossbill. Unless they are thoroughly well 

 identified and authenticated they are worthless as scien- 

 tific specimens. The locality is of some small service in 

 the matter of identification. 



Family FRINGILLID^. Genus LoxiA. 



Sub-family FRINGILLINM. 



EUROPEAN WHITE-WINGED CROSS- 

 BILL. 



LoxiA BiFASCiATA {Bre/wi). 



(British : Rare nomadic autumn and winter migrant.) 



Number of broods unknown. Laying season, apparently 

 unknown. 



Breeding area : Northern Palaearctic region. The 

 European White-winged Crossbill breeds in the pine 

 forests of Northern Russia and Siberia, as far east as 

 the Pacific coast, where it was observed by Middendorff 



