MONOGRAPH OF THE PETRELS. 



eyelid white above and below ; cheeks for the most part white, mottled with ashy- 

 grey ; sides of neck, behind the ear-coverts, also white, mottled with ashy frecklings ; 

 throat and remainder of under-surface pure white ; the sides of the lower throat, 

 fore-neck, and chest mottled with sooty or ashy-brown, where they adjoin the sooty- 

 brown of the back ; on the thighs a patch of black feathers ; under-tail coverts white, 

 some of the long lateral coverts externally sooty-black ; under wing-coverts and 

 axillaries white, the latter with a spot of ashy or sooty-black near the ends ; a slight 

 ashy-grey mottling all round the bend of the wing ; quills dusky-brown below, the 

 inner webs of a more ashy-grey shade ; " bill dark horn-colour, the sheath of the under 

 mandible greyish ; back of the tarsus, outer toe, and lower outer half of middle toe 

 black ; iris dark brown ; tarsus in front, and toes light pink, the webs bluish-grey, 

 paler in the middle " (W. R. Ogilvie-Grant). Total length, 14.5 inches ; culmen, 1.45 ; 

 wing, 9.5 ; tail, 3.0 ; tarsus, 1.7 ; middle toe and claw, 2.15. 



Adult male. Similar in plumage to the female. Total length, 14.5 inches ; 

 culmen, 1.3 ; wing, 9.0 ; tail, 2.9 ; tarsus, 1.7 ; middle toe and claw, 1.85. 



Nestlings. Covered with sooty-brown down. 



Obs. Sometimes the sub-terminal black spot on the axillaries is very large, at other 

 times it is divided into twin-spots, and in some specimens it is very minute, 

 suggesting that, in very old birds, it becomes evanescent and may disappear altogether 

 with age. 



Occasionally there are frecklings of black on the lower flanks, or even black streaks. 

 It is evident, however, that these markings on the flanks and axillaries are never brown 

 as in P. yelkouanus, but are always black in P. anglorum, and the under tail-coverts 

 are also never brown, as in the Levantine Shearwater. 



The description of the male is taken from a specimen from St. Bride's, South 

 Wales, presented to the Museum by the late Lord Kensington ; that of the female 

 from an example in the Howard Saunders Collection, from Rathlki Island. The 

 specimen figured is the male above recorded. 



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