MONOGRAPH OF THE PETRELS. 



sent me a full description and measurements of the type-specimens of P. chlororhynchus. 

 The length of the centre tail-feather is 118 mm. ( =4.7 inches), and of the outer feathers 

 80 mm. (=3.2 inches). 



No specimen of P. tenuirostris or P. carneipes examined by me has a tail exceeding 

 4.5 inches in length, and consequently the type of P. chlororhynchus seems to 

 be identical with the bird which was described by Gould as P. sphenurus. Without 

 comparing the actual specimen, it is, of course, somewhat difficult for me to give a 

 decided opinion, but the details kindly supplied by Dr. Menegaux seem to leave little 

 doubt on the subject. 



I can find no specific characters in the dimensions of specimens from eastern and 

 western localities, as is proved by the series in the British Museum and the Rothschild 

 Collection. 



Wing. 



Culmen. 



Tarsus. 



Middle toe 

 and claw. 



Mauritius, etc. 10.2—11.5 



. . 1.4—1.5 



. . 1.7—1.9 . 



. 2.25—2.5 



Australia, etc. 11.0 — 12.5 



.. 1.35—1.7 . 



. 1.7—2.1 . 



. 2.1—2.5 



It will be observed that, although the Australian birds are slightly larger, there 

 is a gradation in size in the Mascarene examples, which approaches that of the 

 Australian form ; but those from the Kermadec Islands, as already pointed out 

 by the late Captain Hutton, are certainly larger than the general run of Australian 

 birds. He gives the following measurements : — " Wing, 12.75 inches ; tail, 6.5 ; culmen, 

 1.65, tarsus, 1.9 ; middle toe and claw, 2.2." I also find that Kermadec specimens 

 in the British Museum and in the Rothschild Collection are slightly larger than 

 Australian examples as regards the length of wing. They measure : — 

 Wing, 12.1-12.5 inches; culmen, 1.55-1.7; tarsus, 1.9-2.1; middle toe and claw, 

 2.3-2.5. There is nothing here which would suggest a specific distinction for the 

 Kermadec bird, though the plumage is somewhat darker than in those from Australia. 



The evidence as to the difference in the colour of the bill and feet in the eastern 

 and western birds cannot yet be considered satisfactory. Gould gives them as 

 follows : — " Bill reddish fleshy-brown, darker on the culmen and tip ; legs and feet 

 yellowish flesh-colour." These do not agree with the Plate in his folio edition of the 

 " Birds of Australia," where the bill is rendered of a blackish colour throughout. 

 Buller, in his " Birds of New Zealand," says that the bill is greyish-black, the legs and 

 feet yellowish-brown. Salvin (Cat. Birds Brit. Mus., XXV., p. 372) gives the colours 

 as follows : — " Bill flesh-colour, the tip dark ; tarsi and toes flesh-colour, the outer 

 toe darker, especially on the joints of the phalanges." Mr. Robert Hall (Ibis, 1902, 

 p. 104) dissents from Salvia's statement, and says that a specimen obtained by him 

 on Houtman's Abrolhos, had the bill " slate-colour, with the tip or nail black, and 

 the feet fleshy-white." In a bird obtained on the Kermadecs by the Earl of Ranfurly 

 the colour of the feet is given as dull yellowish. 



86 



