MONOGRAPH OF THE PETRELS. 



Phil. Trans., Vol. 168, p. 137). Mr. R. Hall (Ibis, 1900, p. 29) relates that he saw 

 P. desolatus in countless numbers in Royal Sound, Kerguelen Island, where they breed, 

 frequently in old rabbit holes. The nests are composed of stalks of coarse seaweed, 

 with stems of limp grass in the centre ; the eggs are clear white when fresh. 



Mr. E. W. Oates gives the measurements, Axis, 1.8-2.05 inches, diameter, 

 1.24-1.46. 



Adult male. Similar to P. banksi, but of a slightly paler and more delicate 

 bluish-grey, the head not being perceptibly darker than the back, and the dusky grey 

 streak from the eye along the upper edge of the ear-coverts not quite so pronounced ; 

 " bill bluish-grey, darker on the sides, and inclining to black at the base ; legs and feet 

 light blue, tinged with green in front, the webs whitish-grey ; iris brownish-black " 

 (Buller). Total length about 10.5 inches ; culmen, 1.05 ; wing, 7.25 ; tail, 3.55 ; 

 tarsus, 1.2 ; middle toe and claw, 1.5. 



Adult female. Similar to the male. Total length, 10.2 inches ; wing, 7.2 ; tarsus, 

 1.2 ; middle toe and claw, 1.35. 



The male described is from Royal Sound, Kerguelen Island, collected by the 

 Rev. A. E. Eaton; the female is from Betsy Cove, Kerguelen Island {Voy. H.M.8. 

 " Challenger''''). The specimen figured is a male, also from Betsy Cove, and all three 

 examples are in the British Museum. 



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