MONOGRAPH OF THE PETRELS. 



Giglioli as quite different from that of (Estrelata, being swift but irregular, the wings 

 being frequently opened and shut rapidly, recalling the flight of certain Doves, especially 

 that of the Turtle Dove. It feeds chiefly on cephalopods. 



Adult. General colour above blue-grey, the long scapulars black towards the ends, 

 which are broadly tipped with white ; wing-coverts like the back, edged with paler 

 grey, the lesser and marginal coverts blackish, as also the bastard-wing, primary- 

 coverts and primaries, the latter white or greyish along the inner web ; inner primaries 

 slaty-grey, blackish towards the ends ; secondaries lighter grey, the innermost blackish 

 for the greater part of the outer web ; on the rump a patch of black ; sides of the rump, 

 upper tail-coverts and tail-feathers blue-grey, the centre ones with a broad black bar, 

 disappearing towards the outermost feathers, which have black ends and black shafts ; 

 crown of head darker grey, the feathers having dusky centres, more distinct towards 

 the forehead, where the centres to the feathers are smaller ; lores greyish, the feathers 

 below the eye greyish-white, slightly spotted with ashy ; the ear-coverts bluish-grey, 

 blackish along the upper edge ; cheeks and under-surface of body pure white, the sides 

 of the foreneck and sides of chest blue-grey ; the lower flanks and under tail-coverts 

 light blue-grey, the bases of the latter white, the long coverts black, with ashy bases ; 

 under wing-coverts, axillaries, and quill-linings pure white. Total length : 11.5 inches ; 

 culmen, 1.3 ; breadth of bill, 0.8 ; wing, 8.4 ; tail, 3.9 ; tarsus, 1.25 ; middle toe 

 and claw, 1.75. 



A specimen from Pitt's Island, Chatham Group, has the soft parts thus recorded 

 on the label : — " Bill light blue, deepening into black on the sides of the nostrils and at 

 the tip, with a black line along the sides of the under mandible ;* feet beautiful light 

 blue ; iris dark brown." The example obtained off Gough Island by the naturalists of the 

 Scottish Antarctic Expedition had the soft parts as follows : — " Lower plate of mandible 

 pale blue, and the remainder of the bill black ; tarsus and toes cobalt-blue ; webs black." 



The measurements of a series of specimens in the British Museum are as follows : — 

 Length of culmen, 1.2-1.4 inch (£1.2-1.3 ; ? L3). 

 Breadth of culmen, 0.6-0.9 inch (<? 0.65 -0.9 ; ? 0.6). 

 Wing, 7.5-8.2 inches (<? 7.35-8.1 ; ? 7.5). 

 Tarsus, 1.25-1.45 inch (£ 1.25-1.45; ? 1.4). 

 Middle toe and claw, 1.45-1.65 inch (c? 1.45-1.6 ; ? 1.6). 



From the few examples in the British Museum which are sexed, the female 

 appears to be a trifle smaller than the male. 



The bird described was captured by Dr. G. A. Davidson during the expedition 

 of the relief ship " Morning," November 11th, 1902. The figure is taken from a New 

 Zealand specimen in our collection. 



* In a drawing of a fresh specimen from Gough Island obtained by the Scottish Antarctic Expedition, 

 the bill is represented as black ; the lower part of the lower mandible only is grey-blue. 



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