MONOGRAPH OF THE PETRELS. 



hind-neck and sides of neck being slaty-grey ; the upper part of the back ashy-grey, 

 mottled with concealed white bases to the feathers ; lores and sides of face dusky black, 

 washed with ashy-grey ; fore-part of cheeks browner ; hind cheeks and entire 

 under-surface of body pure white, the sides of the body mostly ashy-brown ; under tail- 

 coverts ashy-brown, those near the vent for the most part white ; axillaries and under 

 wing-coverts ashy-brown, the central coverts rather more hoary in appearance, many 

 of the coverts being edged with ashy-grey ; quills dark brown below, ashy-grey on the 

 inner webs ; " bill perfectly black on the ridge, changing to horn-colour on the hook, 

 and having a black line down the middle of the lower mandible, widening out on 

 meeting the unguis, which is dull horn-colour ; legs and feet greyish flesh-colour, shaded 

 with slaty-grey on the heel and on the outer side of the tarsus and toes ; interdigital 

 webs yellowish, with grey edges " (Buller, Suppl. Birds New Zeal., I., p. 106). Total 

 length about 19.5 inches ; culmen, 2.0; wing, 13.1 ; tail, 4.3 ; tarsus, 2.3 ; middle toe 

 and claw, 3.2. 



The colour of the soft parts varies to a considerable extent. The late Nikolai 

 Hanson states that specimens obtained by him in October, in the Cape seas, had the 

 " bill horn-colour, yellowish on the upper mandible from the nostrils to the tip ; 

 feet, including the webs, grey ; iris dark brown " (Sharpe, Rep. Voy. " Southern 

 Cross" Aves, p. 142, 1902). Professor Giglioli {Faun. Vertebr. Oceano, p. 34) gives the 

 following notes made on specimens procured in the Atlantic and Indian Oceans, 

 during the voyage of the " Magenta " by the late Dr. De Filippi : — " Maxilla of the 

 palest green, almost white, the nasal tubes and culmen black ; mandible pale horn- 

 colour, with a black line near the edge, widening at the base of the bill and near the 

 culmen, the nail horn-colour ; feet, pale bluish, the toes underneath, and the interdigital 

 membrane, dusky on the margin ; iris grey." 



Dr. E. A. Wilson gives the soft parts as follows : — " Iris dark brown ; upper bill 

 dark greyish horn-colour, the latericorn pale and yellowish, and in some birds, even bright 

 yellow, the mandible greyish-horn at the tip, but otherwise pale yellow, both on the 

 cutting edge and on the sides, a darker line dividing these parts ; legs and toes grey, or 

 fleshy-grey, the webs fleshy-pink, or even red by transmitted light, but otherwise grey 

 or fleshy-grey ; claws blackish horn-colour ; inside of mouth fleshy -red, the palate, fauces, 

 and tongue abundantly supplied with sharp horny papillae." 



Darwin says that " half of the lower mandible and the legs were blackish ; the web 

 between the inner toes, with the exception of the margin, was reddish-lilac-purple, the 

 rest being blackish." 



The specimen described above was obtained in the South Atlantic by Mr. H. King, 

 and was given to us by the late Howard Saunders. The bird figured is the one procured 

 by Dr. A. B. Meyer in the South Atlantic. Both were in our own collection, and are now 

 in the British Museum. 



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