COMMON CROSSBILL. 23 



number. They are pure white, or white with a yellowish 

 tinge, in ground colour, spotted and speckled with 

 purplish-brown, and generally with a few small pale 

 gray underlying markings. The surface of the shell, 

 though somewhat rough in texture, is polished and 

 glossy. As a rule, the eggs of this species do not exhibit 

 much variety. Average measurement, V2 inch in length, 

 by '9 inch in breadth. Incubation, performed chiefly by 

 the female, lasts from fourteen to fifteen days. 



Diagnostic characters : The size, white ground 

 colour, and reddish-purple spots, readily distinguish the 

 eggs of the Golden Oriole from those of every other 

 British species. The unique character of the nest is also 

 another unfailing guide to the identification of the eggs. 



Family FRINGILLTD.^. Genus LoxiA. 



Sub-family FRINGILLINyE. 



COMMON CROSSBILL. 



LoXIA CURVIROSTRA, LiuncEus. 



Single Brooded, Laying season, February to April. 



British breeding area : The Common Crossbill is 

 one of the most local of the species that breed within 

 the limits of the British Islands. In England it breeds 

 locally and irregularly in many of the counties lying 

 south of a line drawn from the Wash to the Bristol 

 Channel ; whilst north of this limit it is known to do so 

 in Yorkshire, Durham, and Northumberland. In Scot- 

 land it breeds more freely, especially in the central 

 counties ; whilst in Ireland it is said by Mr. Ussher 

 to have increased of late years as a breeding species, 



