MONOGRAPH OF THE PETRELS. 



coast near the Castillo rocks, in Uruguay, on October 1st, and also on the 10th 

 of June (Ibis, 1894, p. 212). 



In habits P. griseus does not differ from P. gravis. It breeds in great numbers on 

 some of the small islands off the coast of New Zealand, the nesting places being much 

 harried by the natives, who esteem these Shearwaters as an article of food. The burrows 

 on the Chatham Islands are usually formed in peaty soil, running horizontally for three 

 or four feet and then turning. The nest, a rude structure composed of sticks and dead 

 leaves, is placed at the end of the hole. A single egg is laid, both sexes assisting 

 in the work of incubation, and when the parents return to roost on shore in countless 

 thousands, the noise they make is deafening. If removed from their burrows they flutter 

 about on the ground for some time in a confused way, but eventually make for the sea. 

 Dr. Crowfoot gives the dimensions of eggs taken on Norfolk Island as : Axis, 2.5-2.75 

 inches ; diam., 1.5-1.75. 



Adult female. General colour above dark-brown, with obsolete margins of paler 

 brown to the feathers ; the scapulars darker and inclining to blackish towards their 

 ends ; wing-coverts more blackish-brown than the back ; the quills black, sometimes 

 with a slight greyish gloss, and paler on the inner webs ; lower back, rump, and upper 

 tail-coverts rather blacker than the back ; tail-feathers black ; head and neck like the 

 back ; sides of the face slightly paler and more sooty-black, with the lower edge of 

 the eyelid white ; entire under-surface of body dusky-brown, with a shade of ashy, 

 more distinctly seen on the sides of the face and throat ; axillaries sooty-brown, rather 

 darker than the breast ; under wing-coverts for the most part ashy- white, with blackish 

 shaft-lines, and shaded or mottled with ashy-brown towards the ends, the coverts 

 round the edge of the wing browner ; quills dusky-brown below, slightly greyer on the 

 inner webs ; " bill dull greyish-black, inclining to yellowish-brown on the ridge ; tarsi 

 and toes bluish-grey, the webs yellowish ; iris black " (W. L. Buller). Total length, 

 16.0 inches ; culmen, 1.7 ; wing, 11.8 ; tail, 3.4 ; tarsus, 2.3 ; middle toe and claw, 2.8. 



Adult male. Similar to the female. Total length, 17.5 inches ; culmen, 1.6 ; 

 wing, 12.0 ; tail, 3.5 ; tarsus, 2.3 ; middle toe, 2.7. 



The description of the female is taken from a specimen in the Hargitt Collection, 

 obtained by the late H. Muller in the Faeroes. The male is from Otago, New Zealand, 

 in the Hume Collection. 



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