116 COLYMBID.E. 



sometimes rather more ; from the carpal joint to the end 

 of the longest quill-feather eleven inches and a half. 

 Females are usually smaller, some measuring only twenty- 

 one inches in length, and but ten inches and a quarter from 

 the wrist to the end of the quill-feather. 



The nestling is covered with a thick brownish-black 

 velvety down, lighter in colour on the underparts. The 

 young bird in tirst plumage, from which the upper figure in 

 our illustration was taken, has the crown and hind neck 

 dark ashy-grey, narrowly streaked with white ; the feathers 

 of the back, scapulars, and wing-coverts margined with 

 white. The white border is first interrupted at the extreme 

 end of the feather, leaving the white marks as two long 

 lateral lines. These lines of white diminish in length by 

 degrees, leaving only one white spot on each outer edge of 

 the feather. At each successive autumnal moult the new 

 feathers are much spotted and margined with white ; and 

 this white seems to wear away, leaving the upper parts 

 nearly unspotted. In early summer this is very marked ; 

 by July there is hardly a spot on mantle and wings. 



In the winter plumage the adults lose the red throat, but 

 it would appear that in mature and vigorous individuals 

 this colour is absent for a short period ; thus giving rise 

 to the opinion that birds which had once acquired the 

 dark-coloured throat did not lose it at any season. 



Mr. A. H. Cocks states (Zool. 1883, p. 176) that he has 

 seen, in a local collection at Dover, a small specimen of this 

 Diver with the anterior portion of both tarsi feathered 

 throughout their whole length. 



Albinos are occasionally met with ; a remarkable example 

 which was shot at the Nore is now in the collection of Mr, 

 John Marshall, of Belmont, Taunton. 



