MONOGRAPH OF THE PETRELS. 



Wing. 



Culmen. 



Tarsus. 



Middle toe 

 and claw. 



7.7 



1.0 



1.5 



1.5 



8.0 



1.0 



1.6 



1.6 



8.0 



1.05 



1.5 



1.7 



8.0 



1.1 



1.5 



1.7 



7.7 



1.0 



1.5 



1.65 



7.6 



1.05 



1.5 



1.6 



7.65 



1.1 



1.55 



1.5 



7.5 



1.05 



1.4 



1.45 



7.4 



0.9 



1.5 



1.5 



e male from J 



:luk Island 



have the 



the Seychelles, which have the same dark inner web to the primaries as those of the 

 Pacific Ocean. In all of them the quill-lining is dark ashy-brown. In the Seychelles 

 birds the axillaries are white, but in the females they are slightly mottled with brown 

 at the tips. The under tail-coverts are white, also mottled with brown towards the 

 ends, the lateral ones black with narrow white tips. 



In addition to the above specimens the Hon. Walter Rothschild has lent me his 

 series of P. obscurus, which measure : — 



c? Pelew Islands (Kubary) 



? Do. do. do. 



<$ Ruk Island, Carolines 



c? Do. do. do. 



c? Seychelles (Thibault) 



? Praslin, Seychelles 



<S Do. do. 



¥ Do. do. 



? Isle Cousin (Thibault) 



The birds from the Pelew Islands and the 

 axillaries white, but the female from the latter locality has white axillaries with a shade 

 of smoky-brown at the ends. 



Of the habits of P. obscurus nothing appears to have been recorded, but they are 

 doubtless similar to those of P. bailloni and other allied species. 



Adult female. General colour above sooty-brown, the wing-coverts like the back ; 

 quills and tail-feathers darker and more sooty-black ; head sooty-brown like the back, 

 as also the ear-coverts ; lores slightly mottled with white ; upper and lower eyelid 

 white ; cheeks and under-surface of body, white ; the sides of the lower throat and fore- 

 neck dusky-brown, this colour extending to the sides of the upper breast, the feathers 

 edged with white where they adjoin the white neck and breast, thus producing a 

 broken and mottled fine ; a patch of sooty-black above the thighs ; under tail-coverts 

 sooty-brown, the shorter central coverts white, some of the outer ones more or less 

 brown externally ; under wing-coverts white, with a broad band of sooty-brown feathers 

 round the margin of the wing beneath ; axillaries white ; quills dusky-brown below, 

 the inner webs rather darker. Total length about 11.5 inches; culmen, 1.0; wing, 



8.0 ; tail, 3.1 ; tarsus, 1.6 ; middle toe and claw, 1.6. 



Adult male. Similar to the female. Total length about 11.5 inches; culmen, 



1.1 ; wings, 7.65 ; tail, 3.1 ; tarsus, 1.55 ; middle toe and claw, 1.5. 



The female described is in the Rothschild Museum, and was obtained by Dr. 

 Kubary in the Pelew Islands ; the male is from Praslin, in the Seychelles. The 

 figure in the Plate is drawn from the Manua specimen in our collection. 



128 



