WHITE-BILLED NORTHERN DIVER 5O7 
is now in the Museum at Newcastle. A fourth was 
obtained, December 1872, on Hickling Broad, Norfolk, by 
the late Mr. EK. F. Booth (Norf. and Nor. Nat. Hist. Soc.). 
A fifth was procured in the winter of 1895-6 in Hamp- 
shire, as stated by the Rev. J. HE. Kelsall. A sixth (an 
Immature bird), shot on Loch Fyne, autumn, 1893, was 
identified by Dr. R. Bowdler Sharpe, in the collection of Mr. 
Bulkley Allen, of Altrincham. 
DESCRIPTIVE CHARACTERS. 
PLUMAGE. Adult male nuptial—This Diver in nuptial 
plumage may be distinguished from C. glacialis as follows :— 
“The head and upper neck are glossed with green, while 
the lower neck is tinged with purple (the reverse of the 
arrangement in the Great Northern Diver); the white 
streaks of the transverse band on the throat are not more 
than eight in number, with fewer than ten on the lower 
neck ; the white spots on the scapulars are decidedly longer 
than broad; while those on the flanks and upper tail- 
coverts' are smaller than in the Sub-arctic species; and 
finally, this high northern form is superior in size. Some 
of these distinctive features had attracted the attention of 
the late Sir James Clark Ross, who virtually discovered 
this bird on Boothia in 1830, though it was only named 
in 1859 by G. R. Gray ; but until Seebohm worked out and 
summarised the points of difference (Zool., 1885, p. 144), 
its claims to recognition were somewhat coldly received”’ 
(Saunders, Man. Brit. Birds, 2nd Edit., p. 711). 
Adult female nuptial.—Similar to the male plumage. 
Adult winter, male and female.—Similar to the winter- 
plumage of C. glacialis. : 
Immature, male and female.—Resembles the adult winter- 
plumage. 
Beak. Yellowish-white at all seasons ; under segment 
sharply upcurved from the angle, upper border of upper 
segment straight from the forehead to the tip, deeper and 
stouter than that of C. glacials. 
Freer. Brownish-black. 
Irmers. Reddish. 
Eaes. Resemble those of C. glacialis. 
1 Tn this species the tail consists of eighteen feathers, whereas 
in C. glacialis there are twenty (W. R. Ogilvie-Grant, Cat. Birds Brit. 
Mus., vol. xxvi, p. 501). 
